Troubleshooting: AWS Lambda Websocket not sending response to the client

I have written an AWS Lambda exposed as a websocket. I am trying to send messages back to connected client but the message is not getting posted to the client. I think it is associated with roles but not sure. I already have given the execute-API role but still, it is not working. Need someone who has done this before extensively to help me resolve this issue. I can only do zoom calls and share screen and troubleshoot it together so do not ask me to send you the code.