my phone is not turning on i need to do a back up it is full i just got 2TB

Hi,

You should still be able to power on your iPhone regardless of storage capacity.

I would recommend completing your backup and then updating to iOS 15.4.1.

Note that iCloud Storage will not resolve any issues related to device storage overcapacity.

The following articles should be able to further assist:

• Update your iPhone, iPad, or iPod touch with iTunes
• How to back up your iPhone, iPad, and iPod touch
• How to check the storage on your iPhone, iPad, and iPod touch
• What's the difference between device storage and iCloud storage?

Hello ~ Take a look here:

If your iPhone, iPad, or iPod touch won't turn on or is frozen

~Katana-San~