After installing TWRP
twrp-3.2.1-0-zeroflte.img.tar with Odin
Odin3_v3.13.1.zip (Don't forget to un-tick "Auto Reboot" in Options tab)...
Install Minimal ADB and Fastboot
minimal_adb_fastboot_v1.4.3_setup.exe
Download and copy
SuperSU-v2.82-201705271822.zip
or Magisk
Magisk-v16.0.zip to Minimal ADB and Fastboot installed directory
(Default is for 64 bit Windows "C:\Program Files (x86)\Minimal ADB and Fastboot"
and for Windows 32 bit default is C:\Program Files\Minimal ADB and Fastboot)
Reboot to recovery wait 10-20 seconds.. and Open Minimal ADB and Fastboot...
type "
adb devices" if you see a device then for SuperSu type: "
adb push SuperSU-v2.82-201705271822.zip /sdcard"
and for Magisk type "
adb push Magisk-v16.0.zip /sdcard"
Afterwards at TRWP Swipe and tap "Install" and install preferred root SuperSu or Magisk...
If you type "
adb devices" and you don't see the device, at TWRP tap "Mount" and Enable/Disable MTP and you will see device listed...