Do I have to amend my last years return in order to file for property tax refund this year?

No, you don't need to amend.   You can claim the TY 2023 credit in TurboTax when you prepare your MN state tax return, and e-file it, if you qualify.   Here are the full instructions to enter the credit:

1. Sign in to TurboTax and begin your Minnesota state taxes.
2. Answer all the questions until you get to the Other Forms You May Need screen, and select Property Tax Refund (Form M1PR), then Continue.

To mail your M1PR (if you can't e-file):

1. Continue until you get to the Filing instructions screen, and select Print Form M1PR.
2. Mail the printout by August 15 to:

Minnesota Property Tax Refund
 Mail Station 0020
 600 N. Robert St.
 St. Paul, MN 55145-0020

Claiming the credit - MN Dept of Revenue, Do I Qualify?    TurboTax will figure and enter the credit, all you have to do is enter your information.