To do the e-step process on your ender 3, you would need to open your favorite notepad application, copy/paste the g-code on that site, save the text file as .gcode, and get that g-code to your ender 3 (SD card, etc).
The same is true for the extrusion multiplier test - you would set the test up in your slicer, slice it, and then print. Some slicers, like orca slicer and super slicer, have a built in extrusion multiplier test that makes it very easy to do this.
Molten_Moron@lemmings.world 3 months ago
I personally like https://teachingtechyt.github.io/calibration.html for all of the above. It provides gcode and stl files based on your input. I’ve had great success using it for my Ender 3.