Is it too late to contribute to my IRA for 2020 to offset the penalty for early withdrawal in 2020 on IRA used while going thru divorce since we're in 2021?

No, it is not too late to make an IRA Contribution for 2020.  You have up to tax filing deadline of April 15 to do so.

Click this link for info on Tax Tips After January 2021.

Although it's not too late to make an IRA contribution for 2020, an IRA contribution won't do anything to reduce the early-distribution penalty on the IRA distributions that you received in 2020.  A new IRA contribution is not a rollover.