Hey Amit,
We understand that you're having an issue with the responsiveness of your display after installing iOS 14. We want to help! The following steps should help with this: If the screen isn’t working on your iPhone or iPad
We also recommend ensuring your iPhone is updated as a software update was recently released. Do you see software version 14.0.1 when tapping Settings > General > About? If not, you'll want to back up your iPhone, then update the software and apps:
Update your iPhone, iPad, or iPod touch
Update apps or use automatic downloads
Let us know how that goes.
Cheers.