curl --request POST \
  --url https://cloudapi.mailercloud.com/v1/templates/update \
  --header 'Authorization: <api-key>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "id": "AXY",
  "categoryId": 0,
  "html": "string",
  "name": "string",
  "plainText": "string"
}
'

import requests

url = "https://cloudapi.mailercloud.com/v1/templates/update"

payload = {
    "id": "AXY",
    "categoryId": 0,
    "html": "string",
    "name": "string",
    "plainText": "string"
}
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({id: 'AXY', categoryId: 0, html: 'string', name: 'string', plainText: 'string'})
};

fetch('https://cloudapi.mailercloud.com/v1/templates/update', 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://cloudapi.mailercloud.com/v1/templates/update",
  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([
    'id' => 'AXY',
    'categoryId' => 0,
    'html' => 'string',
    'name' => 'string',
    'plainText' => 'string'
  ]),
  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://cloudapi.mailercloud.com/v1/templates/update"

	payload := strings.NewReader("{\n  \"id\": \"AXY\",\n  \"categoryId\": 0,\n  \"html\": \"string\",\n  \"name\": \"string\",\n  \"plainText\": \"string\"\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))

}

{
  "message": "updated template successfully"
}

{
  "error": "html is a required field"
}

{
  "errors": [
    {
      "field": "",
      "message": "Authorization failed"
    }
  ]
}