Deleting Yelp app from IOS

If it's not in your App Library, then it's not on your phone...

see if this helps

How to delete apps on your iPhone, iPad, and iPod touch - Apple Support

you can delete from the App Library by locating the app and tap/hold, select Delete App

or you can go to Settings > General > iPhone Storage > [app name] > Delete

If you still unable to delete, check:

Settings > Screen Time > Content & Privacy Restrictions > iTunes & App Store Purchases > Deleting Apps

make sure that's set to 'Allow'

You can go to the App Library and delete it from there. See this to start with, which has information if you have parental controls turned on, Delete apps on your iPhone, iPad, and iPod touch - Apple Support Then you can take a look at this regarding the App Library, Organize the Home Screen and App Library on your iPhone - Apple Support