curl --request POST \
  --url https://{workspace}.spreesuite.com/billspree/services/update-service \
  --header 'Authorization: <api-key>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "method": "Update",
  "action": "Update Package",
  "apiVersion": "v2",
  "service": {
    "code": "DEMO-001",
    "name": "Demo Plan Updated",
    "serviceType": "Sale",
    "chargingType": "Postpaid",
    "postType": "Post Subscription",
    "billingCycle": 4,
    "dueDateOffset": 15,
    "description": "Updated description",
    "values": [],
    "components": [],
    "connectionInputs": [],
    "meteredInputs": [],
    "unmeteredInputs": [],
    "bankAccounts": [],
    "batches": [],
    "invoiceTemplate": {
      "templateID": null
    },
    "emailTemplate": {
      "templateID": null
    }
  }
}
'

import requests

url = "https://{workspace}.spreesuite.com/billspree/services/update-service"

payload = {
    "method": "Update",
    "action": "Update Package",
    "apiVersion": "v2",
    "service": {
        "code": "DEMO-001",
        "name": "Demo Plan Updated",
        "serviceType": "Sale",
        "chargingType": "Postpaid",
        "postType": "Post Subscription",
        "billingCycle": 4,
        "dueDateOffset": 15,
        "description": "Updated description",
        "values": [],
        "components": [],
        "connectionInputs": [],
        "meteredInputs": [],
        "unmeteredInputs": [],
        "bankAccounts": [],
        "batches": [],
        "invoiceTemplate": { "templateID": None },
        "emailTemplate": { "templateID": None }
    }
}
headers = {
    "Authorization": "<api-key>",
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.text)

const options = {
  method: 'POST',
  headers: {Authorization: '<api-key>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    method: 'Update',
    action: 'Update Package',
    apiVersion: 'v2',
    service: {
      code: 'DEMO-001',
      name: 'Demo Plan Updated',
      serviceType: 'Sale',
      chargingType: 'Postpaid',
      postType: 'Post Subscription',
      billingCycle: 4,
      dueDateOffset: 15,
      description: 'Updated description',
      values: [],
      components: [],
      connectionInputs: [],
      meteredInputs: [],
      unmeteredInputs: [],
      bankAccounts: [],
      batches: [],
      invoiceTemplate: {templateID: null},
      emailTemplate: {templateID: null}
    }
  })
};

fetch('https://{workspace}.spreesuite.com/billspree/services/update-service', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://{workspace}.spreesuite.com/billspree/services/update-service",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode([
    'method' => 'Update',
    'action' => 'Update Package',
    'apiVersion' => 'v2',
    'service' => [
        'code' => 'DEMO-001',
        'name' => 'Demo Plan Updated',
        'serviceType' => 'Sale',
        'chargingType' => 'Postpaid',
        'postType' => 'Post Subscription',
        'billingCycle' => 4,
        'dueDateOffset' => 15,
        'description' => 'Updated description',
        'values' => [
                
        ],
        'components' => [
                
        ],
        'connectionInputs' => [
                
        ],
        'meteredInputs' => [
                
        ],
        'unmeteredInputs' => [
                
        ],
        'bankAccounts' => [
                
        ],
        'batches' => [
                
        ],
        'invoiceTemplate' => [
                'templateID' => null
        ],
        'emailTemplate' => [
                'templateID' => null
        ]
    ]
  ]),
  CURLOPT_HTTPHEADER => [
    "Authorization: <api-key>",
    "Content-Type: application/json"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://{workspace}.spreesuite.com/billspree/services/update-service"

	payload := strings.NewReader("{\n  \"method\": \"Update\",\n  \"action\": \"Update Package\",\n  \"apiVersion\": \"v2\",\n  \"service\": {\n    \"code\": \"DEMO-001\",\n    \"name\": \"Demo Plan Updated\",\n    \"serviceType\": \"Sale\",\n    \"chargingType\": \"Postpaid\",\n    \"postType\": \"Post Subscription\",\n    \"billingCycle\": 4,\n    \"dueDateOffset\": 15,\n    \"description\": \"Updated description\",\n    \"values\": [],\n    \"components\": [],\n    \"connectionInputs\": [],\n    \"meteredInputs\": [],\n    \"unmeteredInputs\": [],\n    \"bankAccounts\": [],\n    \"batches\": [],\n    \"invoiceTemplate\": {\n      \"templateID\": null\n    },\n    \"emailTemplate\": {\n      \"templateID\": null\n    }\n  }\n}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("Authorization", "<api-key>")
	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.post("https://{workspace}.spreesuite.com/billspree/services/update-service")
  .header("Authorization", "<api-key>")
  .header("Content-Type", "application/json")
  .body("{\n  \"method\": \"Update\",\n  \"action\": \"Update Package\",\n  \"apiVersion\": \"v2\",\n  \"service\": {\n    \"code\": \"DEMO-001\",\n    \"name\": \"Demo Plan Updated\",\n    \"serviceType\": \"Sale\",\n    \"chargingType\": \"Postpaid\",\n    \"postType\": \"Post Subscription\",\n    \"billingCycle\": 4,\n    \"dueDateOffset\": 15,\n    \"description\": \"Updated description\",\n    \"values\": [],\n    \"components\": [],\n    \"connectionInputs\": [],\n    \"meteredInputs\": [],\n    \"unmeteredInputs\": [],\n    \"bankAccounts\": [],\n    \"batches\": [],\n    \"invoiceTemplate\": {\n      \"templateID\": null\n    },\n    \"emailTemplate\": {\n      \"templateID\": null\n    }\n  }\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://{workspace}.spreesuite.com/billspree/services/update-service")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["Authorization"] = '<api-key>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"method\": \"Update\",\n  \"action\": \"Update Package\",\n  \"apiVersion\": \"v2\",\n  \"service\": {\n    \"code\": \"DEMO-001\",\n    \"name\": \"Demo Plan Updated\",\n    \"serviceType\": \"Sale\",\n    \"chargingType\": \"Postpaid\",\n    \"postType\": \"Post Subscription\",\n    \"billingCycle\": 4,\n    \"dueDateOffset\": 15,\n    \"description\": \"Updated description\",\n    \"values\": [],\n    \"components\": [],\n    \"connectionInputs\": [],\n    \"meteredInputs\": [],\n    \"unmeteredInputs\": [],\n    \"bankAccounts\": [],\n    \"batches\": [],\n    \"invoiceTemplate\": {\n      \"templateID\": null\n    },\n    \"emailTemplate\": {\n      \"templateID\": null\n    }\n  }\n}"

response = http.request(request)
puts response.read_body

{
  "success": true,
  "statusCode": 200,
  "message": "Request Succeeded.",
  "error": null,
  "data": {}
}