do you have the following?
sidequest installed on a pc
the oculus drivers loaded on a pc
developer account created through oculus
developer account enabled on your quest 2?
if you do its as simple as powering the quest 2 on,
loading up to the home screen in quest 2.
launch sidequest on the pc.
connect the pc to the quest 2 with a data usb cable
look in the headset accept the rsa key by using the touch controllers.
then search for a game o the pc sidequest and click install.
you will see a progress bar letting you know its successful.
then just removing the cable from the quest 2
then filter unkown sources in the quest 2 to see the file.