I wanted to install the game, and I searched up "PSO2" as the FAQ suggested me. It didn't show any results? Is it because of my region (UK)?

PSO2 is only officially available in the USA and Canada. If you want to download it, you need to change your XBox's region.

@AndrlCh ok, thank you for the info.

In addition, it won't appear in the Windows Microsoft Store at all regardless of region due to PC version not being out.