Hi Malnuman,
Please review the Sidequest instruction posted on the page.
You need to use the PC to sideload games. At least the first time.
You can use the PC to sideload sidequest itself too, so that way you only need to use the PC for the first time, but I've never done that myself.
https://sidequestvr.com/community/142/p/2690/how-to-set-up-sidequest-step-by-ste...