Apple storage full cannot buy more space. What Do I do now ?

Are you referring to your iCloud storage or local iPhone storage. You can purchase iCloud storage in settings. Press your name at the top and go to iCloud. Manage Storage and change storage plan.

Are you saying that your iCloud storage is full? Why can’t you upgrade it? You can get 50GB for $0.99 per month.

Are you saying that you cannot upgrade your iCloud storage setting?