1098 for Mortgage Originating in December?

My wife and I purchased a home in December of 2020, but didn't make our first mortgage payment until January of 2021. The home was purchased via a legal,, secured loan from my parents (my parents are acting as the bank). They did not provide us a 1098, though I don't believe that is required.

 

My question is do we need to note anything on our 2020 taxes about the mortgage since the first installment wasn't paid until 2021? Should I complete the steps for the 1098 anyway, and just keep the interest at $0?