Frist, you’ll require a setup of parallel bars, so you have enough space to move your body back and forth.
Firmly grasp the bar.
Now extend your arms to come to a starting position.
Then, push towards the back to lower yourself back and down, onto your forearms.
After that, pull yourself on frontward into the bottom position of a regular dip (elbows at 90°, forearms vertical).
In the end, push yourself up through extending your arms towards the starting position and repeat.