Part of my screen is not responding

Hi,

Do a force restart of your phone.

Check this how to force restart the phone ---https://support.apple.com/guide/iphone/force-restart-iphone-iph8903c3ee6/ios

Remove the screen protectors , if any and check.

if force restart does not help Force restart iPhone - Apple Support

then take it in to where you purchased it for evaluation and be prepared for a screen replacement

iPhone Screen Repair & Replacement - Official Apple Support