My iPhone has been stuck on the Apple logo. What do I do?

Try things in these links:

If your [iOS 13 or higher] iPhone is stuck on the Apple logo - https://support.apple.com/HT210616

If your iOS device restarts or displays the Apple logo or a spinning gear unexpectedly - https://support.apple.com/HT203899

If your iPhone, iPad, or iPod touch won't turn on or is frozen - https://support.apple.com/HT201412

If they do not work then follow the advice at the end of the links about contacting Apple.

samantharosecouto wrote:

I can't restore my phone because my phone hasn't been backed up in months

What you say after “because” is unfortunate, but it won’t prohibit you from doing what you’ll be required to do - restore the iPhone.

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

samantharosecouto wrote:

My iPhone 12 Pro has been stuck on the Apple logo for about an hour now. I tried pressing the bottom and top volume buttons and holding down the power button. I can't restore my phone because my phone hasn't been backed up in months, so I clicked on 'update' to see if that'll work, but it just keeps disappearing and I keep doing this whole process all over again. It isn't working. What do I do?

Sounds like your phone needs recovery.

Go here - If your iPhone is stuck on the Apple logo - Apple Support

For the underlined part:

oh great, your personal data will be lost

I can't restore my phone because my phone hasn't been backed up in months,

So this will be an excellent learning opportunity to back up your devices regularly. ;-) Are you sure you didn't have iCloud set to backup your phone? That is so easy, you just plug it in at night and it gets backed up while you sleep.