Removal of license plate holder

I just purchased the lease on my 2020 Ecosport and now I need only one plate. I had the black plate holder removed but I’m now left with two round holes and another large rectangular one. These holes are shallow and meet up with the black bumper backing behind them. Any suggestions for covering them? I know they sell plugs for the round one but I don’t know what to do with the rectangular one.

These guys hooked me up nicely on my Fiesta. They can match the paint no problem. https://bumperplugs.com/