Request URL: wss://ws-18c9516b-cd88-44cc-a6d7-8a4c7c85d1e0.sendbird.com/?p=JS&pv=Mozilla%2F5.0%20(Macintosh%3B%20Intel%20Mac%20OS%20X%2011_0_0)%20AppleWebKit%2F537.36%20(KHTML.%20like%20Gecko)%20Chrome%2F87.0.4280.66%20Safari%2F537.36&sv=3.0.143&ai=18C9516B-CD88-44CC-A6D7-8A4C7C85D1E0&user_id=8fab1c16-e6ab-4d10-ba5a-dc97340ef7a9&access_token=63103881fec91c9d7ed237bfec33f6b013d18b21&active=1&SB-User-Agent=JS%2Fc3.0.143%2F%2F&Request-Sent-Timestamp=1614968517430&include_extra_data=premium_feature_list%2Cfile_upload_size_limit%2Capplication_attributes%2Cemoji_hash
Response:
Error during WebSocket handshake: 'Upgrade' header is missing