Thanks FM, 

I read the document also check the process at least three times, but still not got inform from admin panel ( discuss page),  1) I open firefox then navigate to my odoo site, not login just start chat with the Welcomebot,  2) I open Chrome and then navigate to my odoo site, login with admin also open discuss page, waiting the message, but nothing received , of course, I typing continue from firefox . 

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I think I found the reason, I got the tips form online document :

LiveChat
The second problematic subsystem for WSGI deployments is the LiveChat: where most HTTP connections are relatively short and quickly free up their worker process for the next request, LiveChat require a long-lived connection for each client in order to implement near-real-time notifications.

This is in conflict with the process-based worker model, as it will tie up worker processes and prevent new users from accessing the system. However, those long-lived connections do very little and mostly stay parked waiting for notifications.

The solutions to support livechat/motifications in a WSGI application are:

Deploy a threaded version of Odoo (instead of a process-based preforking one) and redirect only requests to URLs starting with /websocket/ to that Odoo, this is the simplest and the websocket URL can double up as the cron instance.

Deploy an evented Odoo via odoo-gevent and proxy requests starting with /websocket/ to the gevent port.

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still face problem, anyone can show  a Nginx config example that works fine on websocket (especial for IM chat) ?

thanks all!

Dear,

Conversations initiated by visitors pop up as a direct message, and are shown in Discuss. Therefore, inquiries can be answered wherever you are in Odoo.

Please refer this documentation for further clarification.
https://www.odoo.com/documentation/16.0/applications/websites/livechat/overview/get_started.html