If you were divorced before the end of 2020 then you cannot file as married for 2020. Nothing about your ex-spouse should be on your own return at all. In fact you should start a new account with a new user ID so that you do not encounter a lot of errors and appearances of your ex's data on your now-Single return. Yes---you need to clear and start over. Unless you are doing your ex a favor----it is his job to prepare and file his own tax return as Single now.
CLEAR AND START OVER
https://ttlc.intuit.com/questions/2586254-how-do-i-clear-and-start-over
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