But I already did that and my Face ID still don’t work

If you have already updated iOS to the latest version on this iPhone and it still didn't resolve the issue, you will need to have Apple look at it. Whether that is to take it to an Apple Store or shipping it to them. AFAIK, there are no other options available.

The support article you came here from should have already provided you with that information. At least the part about updating the firmware/contact Apple.

Hello. If updating your iPhone's iOS version does not resolve your issue with Face ID, you will need to contact Apple. Your iPhone will likely need service or a repair.

See the link above. Otherwise, you'll need to make an appointment.