Could you elaborate on what you're asking for? As a HTML file, this should run easily offline both on a PC and on most digital devices, via the free download, as long as that device has a browser.
The roommate's partner wants you to be some distance away for that challenge. If you head toward the park and walk around a bit in that area, an event should automatically fire about sending them a selfie and that completes their challenge.
Even if you fail to do it, it shouldn't be the end of the storyline. They should punish you but then issue you another challenge within a week or two.