Once flashed, you can reboot your device:
If you wish to boot into recovery mode, press and hold the Volume Down + Power button altogether. Now move ahead and root OnePlus 5T using the steps below.
You can either root your device through two different tools. You can either opt for SuperSU, which is a dedicated root solution. Or, you can choose Magisk, which is way more than a root solution and provides support for modules too.
Next, boot your OnePlus 5T into TWRP recovery:
When you boot into TeamWin recovery for the first time, you will be prompted with the system modifications message. Just swipe the ‘Swipe to allow modifications‘ button.
Then, tap on the ‘Install‘ button and select the SuperSU/Magisk root zip.
When the flashing process is complete, tap on the ‘Wipe Dalvik/Cache‘ button. And then press the ‘Reboot System‘ button to boot back into the rooted firmware.
Once your phone boots back, you can go ahead and try root-enabled apps on your OnePlus 5T.
Following the above steps, you can easily install TWRP Recovery and Root OnePlus 5T. If you face any problems while rooting your phone, ping us through the comments.