Hello,
I try to start agent session using conversation api and it always return the below error:
{"errors":[{"UUID":"687d6605-0035-4a3b-842d-25ffad67a954","message":"<html>\r\n<head><title>500 Internal Server Error</title></head>\r\n<body>\r\n<center><h1>500 Internal Server Error</h1></center>\r\n<hr><center>nginx</center>\r\n</body>\r\n</html>\r\n","name":"UNAUTHORIZED"}],"data":null}
I create oauth token with scope "read write chat" and try with below instruction:

Thank you
To make sure your OAuth token is valid, can you confirm if you used this linked OAuth flow to generate your token?
Best,
Erica