"It's because the browser can send only the GET requests that's why"

When we are testing a client-server request on our offline computer (local server) we can do this testing by inserting the URL (IP address and port) into any browser and see if the result is coming or not as the response

but this is only possible when our request is of type GET

but when we want to test POST requests, the browser simply can't do that (it's not designed to send POST requests) in that case we go for another tool called Postman.