My calibration screw looks different than in the video

Although the screw varies from model to model, the concept of tightening (clockwise) for stringy prints and loosening (counterclockwise) for faint prints remains the same. The screw is also found in the same place across all models, in the back left of the print platform. 

For A1, the screw is the same as in the calibration video. 

For A3 pictured below, you can use the right angle screwdriver that was delivered with the printer.

 

For A2 pictured below, you can adjust using your fingers