Maybe I misunderstand you, but the normal step to create a checkbox:
- type
-
, then space; - type
[
, then space, then]
, then space again; - still on the same line type a text for the checkbox.
Now, to place a checkmark, click once on the checkbox when in Preview. This is the normal step when one encounters a checkbox on a webpage.
That’s all there is to it, and it is intuitive. TBH, I don’t find your procedure intuitive.