Arduino has a very simple and effective way to send a keystrokes to the PC. It just takes a single instruction, Keyboard.write and the parameter is the key that we want our board to simulate. As usual, details and more info are available in the official documentation.
I use this instruction to send the F12 key and reset my Track IR.
Keyboard.write(KEY_F12);
I have assigned the big round button of my Radio Box to it since I have the habit of recentering my ancient Track IR v4 quite often.
FlyAndWire 