My headphone jack is not working on my iPhone 7

This is a user to user support forum.

We cannot really do much to fix a hardware issue.

if you have inspected the port, made sure it was free of lint or obstructions, made sure the volume was turned up and not muted, there is nothing we can do.

Take it in for service.

Well, You could have a defective lightning adapter or a dirty charging port. I would have your iphone inspected.

Regards

Giulio