safari v15 is not working on zoom sign in page, I can not get in my account.

There have recently been many reports of new problems with Safari. It seems that the recent Safari update has issues. Word has it that Apple knows about the problems and is working on a fix. I assume that it will be released fairly soon. In the meantime, use another browser such as Firefox or Chrome and they should work for you. Also, there are reports that reinstalling Safari and restarting the computer has resolved issues. I hope this helps.