If you want it like normal choice:
label menu
NARR
What do you want to do?
choice
"start chapter" {
} “skip chapter” {
NARR
Are you sure you want to skipp this chapter?
choice
"YES - skip it" {
goto storyend
} “No, I messed up” {
goto menu
}
}
########################################
NARR
Here write your story
########################################x
label storyend
NARR
To be continued
But this is usually done as a tappable menu with using overlays