use the sandbox(develop2.symphony.com)  that symphony provide to test chatbot. That works on my end. I use the same code same key same configuration in my customer's environment it doesn't work. . I think this could be caused by other issue instead of authorization. Could you think of any possible reason about this? the error message attached below.

 symphony.bdk.gen.exceptions.ApiException: (401)
Reason: 
HTTP response headers: <CIMultiDictProxy('Server': 'nginx', 'Date': 'Wed, 15 Feb 2023 19:52:42 GMT', 'Content-Type': 'application/json;charset=UTF-8', 'Content-Length': '62', 'Connection': 'keep-alive', 'X-Trace-Id': 'tlXWso:rh7ljQ', 'Strict-Transport-Security': 'max-age=63072000; includeSubDomains; preload', 'P3P': 'CP="Symphony does not have a P3P policy"', 'Access-Control-Allow-Credentials': 'true', 'Access-Control-Allow-Methods': 'GET, POST, PUT, DELETE, OPTIONS, HEAD', 'Access-Control-Max-Age': '600', 'Expires': 'Sun, 01 Jul 2001 00:01:02 GMT', 'Last-Modified': 'Wed, 15 Feb 2023 19:52:42 GMT', 'Cache-Control': 'no-store, no-cache, must-revalidate, max-age=0, post-check=0, pre-check=0', 'Pragma': 'no-cache', 'Referrer-Policy': 'strict-origin-when-cross-origin', 'X-Content-Type-Options': 'nosniff', 'X-XSS-Protection': '1; mode=block')>
HTTP response body: {"message":"Cannot authenticate user","status":"UNAUTHORIZED"}