There are no objectives to complete so simply head over to the “?“ in Raton Canyon to begin the mission, then approach the red truck to trigger a cutscene. After the scene, you will find yourself out in Grand Senora Desert near a bunch of satellite dishes. After a while, you will receive a text asking for a donation and linking to Epsilon’s donation page.
Donate $500 to continue to the next mission. An Epsilon icon will appear on your map in Downtown Vinewood. It looks like a strange “E”.