I have the same question, @Catherine_B . I believe @homesmiths  is referring to payments that my company makes on a loan, not loans that we've made to someone else.

My case is that our nonprofit organization has a mortgage loan on a building we own. We have received a grant that can be used for monthly mortgage payments. I have set up a Project to track the grant, but the when I tag the mortgage payment with the appropriate Customer/Project, it does not show up as a Project Expense. Do I have to do this manually through a Journal Entry somehow?