How to delete my cache’ on iPhone XR

1. Empty Caches.

Clear the history, caches and cookies

https://support.apple.com/en-us/HT201265

2. Delete the app manually.

Quote:

Delete content manually

You can check your storage to see how much space your apps use and delete the ones that you don't need.

You can download your purchased apps or other content again later. 

1. On your iPhone, iPad, or iPod touch, go to Settings > General > [device] Storage.
2. Select any app to see how much space it uses.
3. Tap Delete App. Some apps, such as Music and Videos, let you delete parts of their documents and data.
4. Install the update again. Go to Settings > General > Software Update.

https://support.apple.com/en-us/HT203097