It’s on the pull up bar but it’s a rope climb work out.
Really just get hanging with bent elbows and practice raising your legs. Knees to Elbows and eventually just for a Spartan Bonus, Toes to Ceiling.
Because the core work is the neglected piece of the rope climb masterpiece. You can get on a rope with bent elbows and lock your feet in but if after that you still try and climb with your hands you’re still gonna have a bad time.
After you grab the rope you bring your knees to your chest, lock the feet, and stand up. You push down on the rope with your feet and shimmy up your hands up. Once you’re fully stood up you release the feet, bring knees to chest and lock them in again and repeat.
In a good rope climb your hands are doing as little work as possible because no matter what they will be the most taxed.