iPhone won't let me delete apps

If you have Screen Time enabled, go to Settings/Screen Time/Content & Privacy Restrictions/iTunes & App Store Purchases and change Deleting Apps to Allow.

Then try deleting the app again.

Tried this. Doesn't work

You can try going to settings>general>iPhone storage> (app name)> delete app

Without knowing what you tried, please read the Apple Recommended post near the top of this page.