How to install Magictricks from recovery mode?
Try this Magisk app that I obtained from my friend's Repository which will help you to download Magisk.zip that you'll flash via custom recovery only and you'll be rooted

Note: If you haven't installed TWRP or CWM it won't install the zip. Configuring and using Fastboot are the basics you need to be and to flash the recovery though.

If new to these, read this guide here and get TWRP recovery from it