I'd like to know which command you mean.

Make sure you subscribed to the base mod BSMod. To make testing easier, you can change these parameters from the spawnmenu/options/bsmod.
But to trigger a killmove you have to use the console and type for example:

bind g bsmod_killmove

...to killmove someone by pressing g.

I have used the command given in the description and have that exact key binded out for killmove plus I have BSMod but unfortunatly it still does not work :(

Did you also tried to change these variables in the spawnmenu options, does it work?
With the command line is rather the chance that you make typing mistakes, that happens to me often.

i literally put bind k bsmod_dropkick in the console
it doesnt work
unknown command