You can access the gyms listed on the cult.fit app by buying a cultpass ELITE or a cultpass PRO.

cultpass ELITE will give you unlimited access to all gyms in a city
cultpass PRO will give you unlimited access to all PRO gyms and 4 sessions per month at ELITE gyms or cult centers in a city.

In addition to gym access, you get unlimited access to LIVE workouts with both the cultpasses