passcode

Do you have a case and/or a screen protector that can interfere withe that screen's area? Should be this case, try and remove both.

Shouldn't be this case, it sounds like a screen (digitizer?) failure, but we can't diagnose that issue remotely, sorry.

Have your device inspected at an Apple Store or Authorized Service provider: Apple – Location Selector

Regards

Giulio

On keypad? Try Re-installing the keyboards, if no success...

take your device to an Apple Retail Store or Apple Authorized Service Provider, or contact Apple Support:

Apple Repair and Repair Status Check - Official Apple Support

https://support.apple.com/repair

Apple Authorized Service Provider

https://locate.apple.com › Home › Find Locations

Find Locations - Location Selector - Apple

https://locate.apple.com › Find Locations

Contact Apple for support and service - Apple Support

https://support.apple.com/en-us/HT201232

If the screen is not working properly or accepting input, you will have to get the phone fixed or you won’t be able to unlock it. If this is a new issue that just came up, did you try restarting the phone?