Offloading the app will free up storage space while still keeping its documents and data. If and when you reinstall the app, your data will be there.
Before you clear the cache on your iPhone, make sure you know your passwords since deleting your cached data might log you out from some accounts.
Offloading differs from a deletion, in that it leaves your stored data intact while erasing the app's data.
How to Offload your App:
Open the Settings app then Select General.
Tap iPhone Storage.
Scroll and Select the SignOnSite app.
Then tap Offload App.
Select Offload App from the pop-up window to confirm your choice.