Hotmart – issues to send order via API from my website to hotmart

I am using Laravel 12 with mysql and deploying my solution using docker to coolify. The payment process I want to setup using Hotmart. I have finished a product configuration and I want to use hotmart API to send Orders. I do not want to use the hotmart checkout page because the experience for the users is not good. I want seamless and integrated solution. Using API I can share my credentials and get back an temporary token, which I tried to use to send an order. The API status return 200 – success, but there is not content in the response. Nothing happened.

example of request command:

{"method":"post","url":"https://developers.hotmart.com/payments/api/v1/subscriptions","data":{"buyer":{"name": ......

example of return:

{"status":200,"content_type":"","is_json":false,"body":""} 

I’ve tried many different endpoints. Anyone here have experienced a simular issue and can contribute to the solution? Many thanks in advanced.