A weapon-buddy box. Did that back in 2001 for the Project series of heavies.

If I can do that, anybody can do it.

Simple enough. The trigger/buddybox is an old commodore 64 joystick with the base removed.
Originaly, I put parallel wiring over the 7th channel of de Multiplex Commander 2020 TX and routed that over a 3.5mm earphone plug. The TX has the plug, the joystick handle has a meter or so stereo headphone wire and the jack.

But now, that buddybox is mated to a Spectrum DX6 and the 2 triggers are made seperate so you can command 2 actions.

With modern technology, I wouldn't be surprised if creative minds and hands can make such a setup wireless.

Oeps, with the current pricetags of the 2.4GHz RX/TX sets, why bother, just buy 2 and get the wiring in the robot a tad creatieve

The most creative buddybox I ever have seen, was the weaponcommand of Krab bot.