A CRP is a Certificate of Rent Paid that a landlord would complete and give to their renter's to certify the amount of rent paid during the year.
To claim a renter's property tax refund in MN, you need to have a CRP from your landlord and you must include the CRP with your return.
See more information below:
https://www.revenue.state.mn.us/individuals/prop_tax_refund/Pages/Renters_Property_Tax_Refund.aspx