my iPhone 12 Pro max is stuck on the Apple Logo screen, what should 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.