boot.img:
https://drive.google.com/file/d/1zyt0ce5urLqvj4KaeCP68tqY3V0lrPDO/view
Magisk manager/install/select and patch file (boot.img)
Copy magisk_patched.img to your PC.
And run:
fastboot flash boot_a magisk_patched.img
fastboot flash boot_b magisk_patched.img
fastboot reboot
Now you have...