If a feature allows you to affect a roll after the result has been totaled, you can use it after the GM declares whether the roll succeeds or fails, but not after the consequences unfold or another roll is made.
Using Features After A Roll
If a feature allows you to affect a roll after the result has been totaled, you can use it after the GM declares whether the roll succeeds or fails, but not after the consequences unfold or another roll is made.