I want to face passcode

See if anything here helps 

Face ID on your iPhone or iPad Pro.  *

Face ID - If an alert says has been disabled on your iPhone or iPad Pro.  *

Face ID not working.   -

Face ID not working' problems on iPhone.    -

Face ID Not Working.   -

Your phone might need service. See this article and follow the instructions provided to see if you can solve it yourself, or that you need to contact Apple Support to get your device serviced.

When Face ID is not working on your iPhon… - Apple Community