One of the biggest drawbacks of rooting is that the monthly update can be tricky with every new security patch. For other phones, you may have had to completely remove the device from the root directory, perform inventory recovery, or even update all factory images to get a new update. Fortunately, OnePlus has made this process very easy for us modders.
In the earlier days of the root scene, it was a bit complicated, but you can now easily upgrade to new devices like OnePlus 6 or 6T, as long as you can still maintain root access. It's almost as simple as native downloading and installing an OTA update on a standard device, but not completely . I'll show you the few quick steps you need to do to update your OnePlus 6T without worrying about the entire tire-jumping.
When you start updating your OnePlus 6 or 6T, you must first download the latest update file from the official OnePlus website to your phone's internal memory. The file is quite large and can take up to ten minutes, depending on the network connection.
It is important that you have the TWRP installer in the internal memory of your phone for safekeeping. The reason for this is that you can permanently flash TWRP after applying the OTA update. Otherwise, stock recovery will be restored to your system.
So, go to one of the following links from your phone and search for the latest version of TWRP. The links may not be okay. Pay attention to the date column on the right and select the link next to the latest date. From there, tap the first "Download …" link on the following page.
As with TWRP, you should have the latest Magisk installation ZIP file in your phone's internal memory so that you can flash it after applying the update. If you skip the Magisk Flash before the next boot, you may find yourself stuck in an endless boot loop after installing the OTA update. Magisk needs to be flashed to install a few patches after the update, so you can boot properly with Android again.
To download the latest version, click on the following link. Tap Assets to expand a menu, and then select the first link (the APK link) from the options displayed.