You can find the movie on several major platforms that offer a "download for offline viewing" feature through their mobile apps:
Tip: Most apps allow you to choose the video quality (Standard vs. High Definition) to save storage space. Project X Movie Download For Mobile
Project X is frequently available in the Max library. If you have a subscription, you can tap the Download icon (a downward arrow) on the movie's page to save it to your phone. You can find the movie on several major
You can rent or buy the movie directly. Once purchased, the Prime Video app allows you to download the title to your device. Project X Movie Download For Mobile