How to click on labels generated by the measurement tool

[俊翔]

Please forgive me if I make any errors.
My English is pretty basic.

I have a task on my frontend job.

The requirement:
Want to clicking labels, and can be copy values.

How to make the Label to clickable ?

i am too beginners in WebGL, ThreeJS, Potree..
past few days, I have done various addEventListener,
but the object of label cannot be found..

Thanks.