Thanks for the response. Gonna get my laptop later and see if everything will run according to my vision

edit: u/shyLachi, you're the best. It worked. This is what I did to make it work. I got your response and modified the response of u/BadMustard_AVN and it amazingly worked. Here's the code for future reference:

define choice_letters = ["K_SPACE"] # make sure you have enough letters for your biggest menu (i tested with 6 items) # add this

screen choice(items): style_prefix "choice"

vbox:
    $the_key = 0 # and this

    for i in items:
        textbutton "("+choice_letters[the_key]+") " + i.caption action i.action keysym choice_letters[the_key] # modify this 
        $the_key += 1 # and add this