Iphone Photo Storage - is it possible.......?

I have an iPhone 12Plus. I am a photographer who creates

galleries on my PC then sync’s them to my phone and Ipad. The Iphone 12 didn’t

offer much memory and my newer iPad has 1TB. My phone is running out of space

and to upgrade the IOS I have to delete galleries then re-sync afterwords. I am

wondering if there is a drive that can be connected to the phone (old

connection) that I can access, when connected, to view/display photos on the

phone. The Ipad has a USB-C connection and aside from the onboard memory I also

carry a portable backup drive that I can access any type of file with, Word,

Excel, etc., plus I can save to that drive and later connect to my laptop and

move files onto it.

Yes, I acknowledge the easiest fix is to buy a new phone

with 1TB and the same flexibility as the iPad, however I am holding out for the

17. For now, I just want to have photo availability/flexibility on the iPhone

12.

I don’t use and won’t use iCloud.

Thank you for any illumination if this is possible.