How do you get skeletal archers to fire their smoke bombs?

I'm in Act 2 now and I've never seen my archers fire their smoke bombs even once. It says to use the "corresponding command skill", but I've looked everywhere and no such skill seems to exist. The "Skeletal Sniper" skill itself cannot be dragged to the action bar like others. There is a key (`) bound to "direct minions", but it does nothing so far as I can tell. How are you supposed to "command" them?

You need to map it to a key/mouse click - like other normal skills.

then when you use it your archers will fire that skill.

Map _what_? The skill itself CANNOT be mapped. "Skeletal Archers" (and other summons) cannot be dragged to the action bar. What am I supposed to be mapping?

Never mind, finally found it after 12 hours of gameplay lol. You CANNOT drag it from the "skills" page like every other skill, but you can click on an empty slot in the action bar and choose it that way.