If I didn't contribute to an RRSP in 2024, do I still put the minimum repayment amount for 2024 into the box that indicates the designated repayment amount?

[TurboTaxSusan]

No. If you didn't contribute to your RRSPs and then you can't designate a contribution as a repayment. The minimum repayment amount will be added as RRSP income on line 12900 of your return.