My iPhone Face ID is not available at this time.

Follow these steps, testing after each step:

• Face ID not working.
• Software Update.
• Turn iPhone on or off.
• Force Restart iPhone.

If that didn’t work and there were no error messages, then get live expert assistance by contacting Customer Support by phone or chat:

• Call Apple Support at 1-800-APLCARE. 📞
• International Support. 🌐
• Contact Apple Support. 📝
• Live chat using Messages. 💬

This may be useful - If an alert says Face ID has been disabled on your iPhone or iPad Pro - Apple Support