Hi GrammaThom,
Thank you for using the Apple Support Communities! To help isolate the issue, are you receiving a storage alert for your device storage or iCloud? We ask because device storage is set and cannot be upgraded as noted in the following article:
What's the difference between device storage and iCloud storage?
Device storage
An Apple device like an iPhone, iPad, or Mac comes with a set amount of storage. The more storage your device has, the more music, apps, photos, and other content you can store on that device. If your device storage is almost full or full, you might get an alert.
Here's how to check the amount of device storage you've used and, if needed, how to optimize and manage your storage space.
Check the device storage on your iPhone or iPad
1. Open the Settings app.
2. Tap General.
3. Tap iPhone Storage or iPad Storage to check the amount of device storage that you've used.
Thank you.