Change RTL_ALT to one click

I’m trying to change the safety height by clicking on my Herelink screen, however, I can’t get the parameter values ​​to be saved and it is recorded as RTL_ALT

This is the code where it ends up saving, the code that comes by default in QGroundControl

And in the other image is the code I’m building

I would like some help identifying why it doesn’t work this way, any tips are welcome and we can discuss