Download Magisk's zip file of the Canary release from
https://github.com/topjohnwu/Magisk, copy it to anywhere in your phone. Boot to TWRP, tap on Install > Select storage > choose the location where the Magisk zip file was copied to > tap on the file > slide the bottom to install > Reboot to system.
When your phone is up and running, launch Magisk, tap on the gear icon (on the top) and turn on the Magisk hide switch. Tap on Systemless hosts. Tap also on Hide Magisk Manager > choose any name > Reboot. When your phone is up again, launch the app whose name you changed. Tap on the shield icon on the bottom > Magisk hide and turn on the keys for apps which would accuse your phone of being rooted, like banking and working apps.