curl --request POST \
  --url https://app.base44.com/api/apps/{app_id}/custom-email-domains/replace \
  --header 'Content-Type: application/json' \
  --header 'api_key: <api-key>' \
  --data '
{
  "domain": "mail.example.com",
  "sender_name": "Nordwind Furniture",
  "from_email": "no-reply@mail.example.com"
}
'

import requests

url = "https://app.base44.com/api/apps/{app_id}/custom-email-domains/replace"

payload = {
    "domain": "mail.example.com",
    "sender_name": "Nordwind Furniture",
    "from_email": "no-reply@mail.example.com"
}
headers = {
    "api_key": "<api-key>",
    "Content-Type": "application/json"
}

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

print(response.text)

const options = {
  method: 'POST',
  headers: {api_key: '<api-key>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    domain: 'mail.example.com',
    sender_name: 'Nordwind Furniture',
    from_email: 'no-reply@mail.example.com'
  })
};

fetch('https://app.base44.com/api/apps/{app_id}/custom-email-domains/replace', 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://app.base44.com/api/apps/{app_id}/custom-email-domains/replace",
  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([
    'domain' => 'mail.example.com',
    'sender_name' => 'Nordwind Furniture',
    'from_email' => 'no-reply@mail.example.com'
  ]),
  CURLOPT_HTTPHEADER => [
    "Content-Type: application/json",
    "api_key: <api-key>"
  ],
]);

$response = curl_exec($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://app.base44.com/api/apps/{app_id}/custom-email-domains/replace"

	payload := strings.NewReader("{\n  \"domain\": \"mail.example.com\",\n  \"sender_name\": \"Nordwind Furniture\",\n  \"from_email\": \"no-reply@mail.example.com\"\n}")

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

	req.Header.Add("api_key", "<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://app.base44.com/api/apps/{app_id}/custom-email-domains/replace")
  .header("api_key", "<api-key>")
  .header("Content-Type", "application/json")
  .body("{\n  \"domain\": \"mail.example.com\",\n  \"sender_name\": \"Nordwind Furniture\",\n  \"from_email\": \"no-reply@mail.example.com\"\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://app.base44.com/api/apps/{app_id}/custom-email-domains/replace")

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

request = Net::HTTP::Post.new(url)
request["api_key"] = '<api-key>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"domain\": \"mail.example.com\",\n  \"sender_name\": \"Nordwind Furniture\",\n  \"from_email\": \"no-reply@mail.example.com\"\n}"

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

{
  "domain": "mail.example.com",
  "status": "pending_domain_verification",
  "email_domain_id": "68b1c0d4e7b91d003c45a1f2",
  "external": false,
  "dns_records": [
    {
      "name": "em1234.mail.example.com",
      "status": "pending",
      "ttl": 300,
      "type": "CNAME",
      "value": "u1234567.wl123.sendgrid.net"
    }
  ]
}

{
  "detail": [
    {
      "loc": [
        "<string>"
      ],
      "msg": "<string>",
      "type": "<string>"
    }
  ]
}