Probe Basic has tool probning built-in, I believe. But it is my opinion that this behaviour does not belong in the GUI....
A more flexible way to do it is via a remap of the M6 command. This would allow you to choose the GUI (and even change it)
There is a sample config sim/axis/remap
/manual-toolchange-with-tool-length-switch/ which might help to show how it all fits together, along with the (very extensive) documentation here:
linuxcnc.org/docs/stable/html/remap/remap.html
Note that most of the docs there can be ignored and you can just copy the relevant files from the sim config to your real config.