The front camera on my IPhone X is not working. The 2x function is fine and the rear camera is fine. What should be done?

I believe it is a hardware issue and the phone has to be serviced by Apple or an Apple authorized service provider.

Review the below 2 articles for more information.

If the camera or flash on your iPhone, iPad, or iPod touch isn't working - Apple Support

Get your iPhone, iPad, or iPod touch ready for service - Apple Support

Apple has decided that you are in need of a new device. Please bring a form of payment and submit your old phone to an apple store to receive a new device, at full cost.

Do you see anything strange, weird things happen when you shake or do something to the camera (When you look at the lens)