Two return shipping labels on one box

I bought iPad Pro and Apple pen Pro online and they were shipped to me in one box. I have decided to return both items and was issued a return shipping label for each item. The tracking numbers and RMA numbers are different between the two labels. I know I shouldn’t tape both labels onto the same box. I don’t want to ship the items separately.

Which label should I tape to the outside of the box? What should I do with the other return label? I assume that I’ll be instructed to put one of the return labels inside the box but really don’t want to screw up and misplace one of the items. Thanks !