No, they send text just as if the user typed it out manually. It is just a custom keyboard that will type out what the buttons have on them.
The result goes into the chat, the query method does not go into the chat. The keyboard can be used many times and hidden and you can go back to the normal keyboard.
The only use case I can see is if I wanted to give a friend abilities to do things in my home without giving them openhab access. You could give them a water lawn button they can press multiple times. But I don’t see it as a good use case as you can automate it in openhab and not need a person to press a button. Any idea I come up with there are better ways to do the same thing.
This thread shows what they look like…
OH3 Telegram Custom Keyboard - Add-ons / Bindings - openHAB Community