If my phone storage is full how do I get it swapped to my iCloud storage?

The iPhone physical storage and iCloud virtual storage are two completely different things and one cannot substitute for the other., The iPhone physical storage is set when you bought the iPhone and cannot be upgraded. For more info, see:

What's the difference between device storage and iCloud storage? - Apple Support

How to check the storage on your iPhone, iPad, and iPod touch - Apple Support

Manage your iCloud storage - Apple Support

Littlemom95 wrote:

But it keeps telling my phone storage is full. I pay for 2T on iCloud. I’m not sure why it tells me storage is full if I have all this iCloud storage?

You cannot move stuff off of your phone and on to iCloud. That's not the way it works. iCloud is a synchronization (and iOS back up) service. The date that is being synchronized exists on both your phone and in iCloud. If you remove it from your phone, it gets removed from iCloud (and any other devices your syncing with).

You can optimize your photo storage to help save space:

Manage your photo and video storage - Apple Support

Your stuff is already on iCloud if you sync your phone. iCloud is a synchronization service, not offline storage.