Why can I have a 403 error code?

I was making many request before, but at once I started to recieve 403 error code. What is the problem?


I tested the issue here, but can not recreate it.
=>If you test the connection with Postman, do you get the same result?

You probably know it, but just in case: Postman is a free app, see Free OCR API

If you see the problem even with Postman, a screenshot of the result could be helpful.