My phone is stuck on the Apple logo and isn't recognized in iTunes/ on my computer.

1. Connect your device to a computer. On a Mac with macOS Catalina 10.15, open Finder. On a Mac with macOS Mojave 10.14 or earlier, or on a PC, open iTunes.
2. Locate your device on your computer.
3. While your device is connected, follow these steps:

• • iPhone 8 or later: Press and quickly release the Volume Up button. Press and quickly release the Volume Down button. Then, press and hold the Side button until you see the recovery mode screen.
  • iPhone 7, iPhone 7 Plus, and iPod touch (7th generation): Press and hold the Top (or Side) and Volume Down buttons at the same time. Keep holding them until you see the recovery mode screen.
• iPad with Home button, iPhone 6s or earlier, and iPod touch (6th generation) or earlier: Press and hold both the Home and the Top (or Side) buttons at the same time. Keep holding them until you see the recovery mode screen.
  • 

1. When you get the option to restore or update, choose Update. Your computer will try to reinstall iOS or iPadOS without erasing your data.
2. 

Your computer will download the software for your device. If it takes more than 15 minutes, your device will exit recovery mode and you'll need to repeat steps 2 and 3.

You may not be able to recover it now. Use the exact process above and preferably on a Mac and you may get the update option but if you can only restore, or you get error 14. Your data is going to be wiped.

Never let any phone or computer memory go past 90% full

See also

https://support.apple.com/en-gb/HT204095