Face id is not available iphone x

Apple's Face ID feature, which allows users to unlock their iPhone X using facial recognition, may not be available for various reasons. It could be due to a software issue, where the feature is temporarily disabled or experiencing technical difficulties. Alternatively, it could be a hardware problem, such as a malfunctioning TrueDepth camera system required for Face ID to work. In such cases, users may need to contact Apple support or visit an authorized service center for assistance.

Go to Settings, tap Face ID & Passcode, then tap Reset Face ID. Next tap Set up Face ID to set it up again.