Hello maureenfromvt,
Thanks for reaching out to the Apple Support Communities! We understand you are looking for some information about a pop up you are receiving about storage on your device. We are happy to help provide some guidance.
It sounds like you may be getting an alert regarding the storage remaining on the device itself instead of the available iCloud storage. Device storage is a set amount that comes on it and isn't able to be increased. You can read the difference between iCloud and device storage here:
What's the difference between device storage and iCloud storage?
We would recommend checking your device storage to see if it is getting full and could be what that pop up is alerting you of:
How to check the storage on your iPhone, iPad, and iPod touch
We hope this information helps.
Best Regards.