How do I regain access to my iPhone after delaying update?

I was setting up my iphone 15, but i clicked wait till later for the software update because i didnt want to update it quite yet, and now i cannot even put my password in to get into the phone, i tried force resetting it, but im at a loss because it wont let me get into my phone, i was able to transfer all of my stuff onto it including my esim, so i cannot even use my previous phone for things like contacting my job, and im unsure what to do.

[Re-Titled by Moderator]