How do I force the section 179 carryover into the 2021 return so that I can claim the deduction?

You most likely need to go year to year. TurboTax should do the carryover automatically after a transfer.

I tried to force the amount in each of the years but I would have to totally redo my tax returns for those years to get the amounts to transfer. For the final 2021 return, Turbo Tax would not let me force the amount where I thought it needed to go.  Since I am just doing my own return and this was a small partnership reported to me on a K-1, I don't want to do that.