To update the OnePlus 3T you need to install an alternate firmware (ROM). If the device does not automatically update by itselves.
You can use the new firmware for your smartphone.
You have to choose the firmware version and follow the instructions. If you have a trouble in update you can write about it in the comments below, we’ll help you.
There is one way for OnePlus update:
If you want to install an OnePlus update using recovery – download the official update, reboot your phone or tablet into recovery mode and click “Install update from SD card”.
If your device does not support automatic updating, you need to install an alternative firmware (ROM).
System update individually for each Android smartphone or tablet. Therefore, there is no universal software or software for updating Android.
You can update Android using the system update tool, download the update for your device in the list and save it to your SD card or internal memory.
In the process of updating Android you may need advanced system settings.
After updating the firmware, you may need instructions on how to get root access to your device.Read more