Now here is how to root your very own OnePlus 7T Pro!
*made sure your bootloader is unlocked!
(Warning: Unlocking your bootloader will wipe your data)
1. Download the patched boot.img
2. Boot into the bootloader
3. Type: fastboot boot pathtomagisk_patched.img
4. Once booted into the phone open the magisk manager app (if not installed manually install it)
5. Go to Magisk's settings and make sure your Update Channel is set to Stable
6. Click the advanced button and made sure preserve force encryption & preserve avb 2.0/dm-verity are turned ON
7. Install Magisk and select Direct Install!