@hunter_tor To get the 3T working with UT, it is Xenial only (16.04), you have to ensure the data partition is EXT4. Use the installer version 0.10.0. Download this version of TWRP and boot it from fastboot - use the command: fastboot boot (location of your TWRP file)
Once in TWRP format date to EXT4, then wipe SYSTEM, CACHE and the others . Reboot to the bootloader and do the same again, but it is not necessary to wipe the system etc, just format the DATA again to EXT4.
Reboot to the bootloader and fire up the UT installer and connect the device and manually select it from the drop down box.
Leave the "wipe data" box unticked and follow the instructions on the installer. Let it do it's thing. Once it is at the screen in your image, leave the device, it can take up to 15 minutes to install.
The OP3 and 3T are very similar, TWRP for 3 and 3T is the same.
Ensure you are on OxygenOS (9.0.6) before starting the UT install.
The two main points of a failed install I have found for the device is using the latest UT installer, use 0.10.0 instead and the incorrect formatting of the data partition to EXT4.
Also as @moem pointed out, the OP3T is old and Xenial is now unsupported... (It still works though).
