Not sure if you're aware but the game is listed as having no available downloads. I can't download it in the itch.io app either
Viewing post in Dungeons & Treasure VR comments
Weird, try it through the website. In the analytics I see people download it and I tested it aswell, it should work. You could also download it from our website: https://www.dungeons-and-treasure.com/index.html. If you still have issues let us know! Have fun!