not able to connect to Stomp server

I'm not sure but when I checked the lib it first calls get request on websocket host address and awaits for 101 switch protocol. In my case even in postman it's not giving 101 but for some strange reason on java end it gives 101 and able to connect from Java lib. Can you look into it? or give me some idea why and what might be the issue I will create pull request after testing the code.