Important information about bump stocks

[LRRPF52]

I don't own a bump stock, so therefore a question: which action or operation initiates the first round to fire? In a plain semi-auto it is the "trigger" finger pulling the trigger back that causes the firing sequence to initiate.
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For the bump stock, is it that same finger? or is it the forward press of the slide/bumpstock (I guess by the other, non-"standard" trigger hand) that initiates the first firing sequence? i.e, for a right-handed person, is the first round initiated by the left hand pulling the slide forward, or is it the right hand trigger finger somehow pulling the trigger?

Maybe someone who knows how these things work can answer.

Your support arm becomes the spring, and also initiates all the pulling of the trigger. Your trigger finger is physically unable to pull the trigger when the bumpstctok is compressed because of the finger block.

Once you pull the firearm itself forward with your support hand, then it fires, and you allow it to somewhat free-recoil between the forward tension from your support arm, which activates the trigger repeatedly until you stop.

It's actually a step backwards from a semi-automatic firearm and much more difficult to fire if you haven't trained with it, very non-intuitive and more of a gimmick.

It's still lethal in trained hands that have taken the time to learn it, as Paddock's brother said he did, however, he could have been far more effective without using the bumpstock, and this is what is ignored in the technical discussion about the nature of bumpstocks.