Yes, learn how federal spending works. Nobody else has to "pay for" federal student loan debt cancellation.
Maybe I'm too simple minded and indeed don't know how federal spending works, but if someone takes out a federal loan for X amount and then has it forgiven, then the federal government didn't get paid back the loan or any interest associated with it. The federal government doesn't have to pay anything new, but it doesn't get paid what it should have. The student received a service (an education), and didn't pay back the loan in full to do so. The student was given an education paid for by whoever funds the government (the people). If you want to argue semantics about whether education should be free, whether someone got a degree that was overpriced, etc, that's a different discussion.
In my little brain, not getting paid back for something is the same thing as having to pay for something. The only difference is that you already paid for it instead of having to pay for it in the future. In the end, said student didn't pay for a service they received, the taxpayer did. Call it what you want.