New to canning, first attempt Peach Jam
It should come out of the bath with the button up and as it cools, the button will pull in with a satisfying pop.
If that doesn't happen the jar might be sealed, but there just isn't a good way to know short of forcing the lid.
If the lid is stuck firmly, without jam having leaked out onto the seal, I would be confident in the seal.
If you really want peace of mind, you can clean the rim, replace the lid with a new one, and process the jar again.