How I Rooted OnePlus 12 with Magisk

There are many conflicting sources on the Internet. Specifically I tried this one and did not work. Below is a short recap what has worked for me.

Short Recap

• Follow Magisk official installation guide
  • OnePlus 12 has ramdisk and uses init_boot.img
  • get oneplus 12 image zip file from this site
  • use payload dumper to extract init_boot.img from here
  • patch init_boot.img and flash the patched version according to the guide
• By now, Magisk should be installed and you should have root access
• Install Magisk Module Manager to install modules
  • for unknown reasons, I could install modules with Magisk app itself, nor through the manual method
• (Bonus) I like to create your own Magisk module. I used the template
  • Specifically if you like to modify a file under /system_ext, please use the path /system/system_ext.
  • For example, if you like to add a file /system_ext/foo, use /system/system_ext/foo instead.

That is it!