iPhone 13 can't hear calls unless on speaker

iPhone 13 about 3 years old suddenly stopped being able to hear from the top speaker on calls. The speaker itself still works because I can hear music and ringtone when I test it, but I can’t hear person on the other end of a call unless I use speaker phone all of a sudden. Did not drop phone or anything that would cause this to happen. I have tried the fixes I found online and nothing works. This is infuriating. The phone isn’t even that old.