You seem to overtook (like most people, so don't feel bad...), that you have the doser, not the doserless model. Take a moment to contemplate on the word DOSER. Did you get an aha moment?
Each doser chamber is about 4 to 6 grams and is adjustable by turning the cone in the middle. So for example if your shot is 18g, adjust the chamber to 6g and fill 3 chambers into the basket.
Watch as first chamber fills up.
Move the handle once.
Watch as the second chamber fills up.
Repeat to fill the third.
Stop grinder (or don't)
Fill up the basket with these first 3 chambers. 1,2,3. Done.
You just need to learn how to use the doser, as a DOSER.