Form 6252 asks for a code for the property type...it is multifamily...what is the code?

It depends as the question requires a bit more detail.

See page 3 of the following link to determine which code is closest to the type of property you need to enter.

Instructions for Form 6252

It appears from the instructions @JotikaT2 provided the code would be "4".  You can enter the installment sale using the step-by-step interview and select the property type (all other) and the code will automatically populate as well.  

When I go the the 6252 form on the .gov site, it does not have the property type question on the 2023 form.  Why does turbotax program require an entry when it is not even asked for on current form?  There is certainly no instructions there one how to fill it out.  This was not asked for on previous years installment sales.