But app not working

You may have downloaded those apps from the Apple App Store, but they were not developed by Apple.

Here is another thing to try … Phone PE requires iOS 14.0m or later. Google Pay requires iOS 13.0 or later. The tags on your post say you have an iPhone 6S. You should be able to update the iOS to 15.75 then use those apps. Try updating your phone.

To update, select Settings > general > Software Update. If your iPhone is eligible for an update, you will be prompted to do so. I hope this helps.

It seems English is not your native language. If you can tell us what your native language is, we may be able to point you to Apple Support in that language.

It looks like you have found the Best Answer to your question. If not, contact Google since it is their app.