If my status says "return filed" but not accepted, is there a way to make changes?

[VolvoGirl]

No.  You have to wait until it is Accepted or Rejected.  Which won't be until the IRS opens Jan 27, 2021 or later.  If it rejects you can fix it and resend it.  But if it is Accepted you have to file an amended return.  That's why you should not file early.

So don't change anything until you know.  And don't click on Amend either!