VKB-SIM

I apologize if this has been asked and answered before but I am unsure of the terminology so couldn't find what I needed...

I am looking to have a button on one of the joysticks simulate pressing a key down, let's say "t", and act as if the key is being held down continuously, with a single press of a button on the joystick.
I would like to then press the same joystick button again to stop the "t" key press.
Is this possible and how would I do it?

For reference, I am playing Elite Dangerous and transferring 1232t of commodities from my FC to/from my freighter is beginning to wear thin.

Thanks for any help you can provide!

It's easy. Watch the video, where the button under the little finger will press the T key and release it when pressed again.