TrueDepth issue

Because the TrueDepth camera contains lasers, they might be disabled for safety reasons if the device malfunctions or is damaged.

Follow the steps here - If an alert says Face ID has been disabled on your iPhone or iPad Pro - Apple Support

deggie wrote:

The True Depth camera does not have lasers it emits Infrared dots.

It does both. According to the Apple article I posted (under the header "What the message means")-

Using diagnostics available in iOS 14.6 or later, Apple has detected an issue with your TrueDepth camera that might cause it to not function as expected. The TrueDepth camera contains lasers, which might be disabled for safety reasons if the device malfunctions or is damaged. (emphasis added) 

Further evidence of this can be found in this Apple article 'About Face ID advanced technology'-

The TrueDepth camera system is safe to use under normal usage conditions. The system will not cause any harm to eyes or skin, due to its low output. It's important to know that the laser system might be disabled for safety reasons if the device is damaged or malfunctions. If you receive a notification on your iPhone or iPad Pro that Face ID has been disabled, you should have a trained technician who uses genuine Apple parts repair your device. Improper repair, modification, or use of nongenuine Apple components in the laser systems might prevent the safety mechanisms from functioning properly, and could cause hazardous exposure and injury to eyes or skin. (emphasis added)

I’ve always found that clause odd unless they used it one time on one device. The True Depth camera is the same as what was used in the Wii Kinect (spelling) which didn’t have any lasers. I’ll stop there on why I made my statement but the end result is the same Apple has to service it to fix it.

The True Depth camera does not have lasers it emits Infrared dots. Go to the last step in the article you came here from and contact Apple Support.