curl --request POST \
  --url "https://siteadresiniz.example/Files/Controllers/ControllersAll.php?main=GoogleMail&container=google_mail_connect" \
  --header "X-API-Key: $ZONELY_API_KEY" \
  --header "Content-Type: application/x-www-form-urlencoded" \
  --data-urlencode 'return_url=ALAN_DEGERI'

const options = {
  method: 'POST',
  headers: {'X-API-Key': '<api-key>', 'Content-Type': 'application/x-www-form-urlencoded'},
  body: new URLSearchParams({return_url: '<string>'})
};

fetch('https://siteadresiniz.example/Files/Controllers/ControllersAll.php', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));