When i refreshed the jitsi screen, my all chat is moved in left side.
When you rejoin, you start a new session and as far as the meeting is concerned, you are now a different user. So in the chat, all the messages are from a different user, hence on the left.
can we set some id, so the chat not move in left side?
On meet.jit.si, I don’t think so since every user there is essentially anonymous.
If you host your own and use a prosody-based auth (secure domain), maybe. I haven’t test this, but I’m assuming once you’re logged in you’ll have a consistent jid and you should then be associated to previous chat messages.