having trouble making a custom action

[MF99K]

Sort of a simple issue, but I can't seem to figure out how to get this action to work:

 

local Action = GLOBAL.Action
local ACTIONS = GLOBAL.ACTIONS
local ActionHandler = GLOBAL.ActionHandler
local TUNING = GLOBAL.TUNING
local STRINGS = GLOBAL.STRINGS

local SIGN = Action({ mount_valid=true })
SIGN.str = "Sign"
SIGN.id = "SIGN"


SIGN.fn = function(act)
    if act.invobject ~= nil then
        local target = act.target or act.doer
        if act.invobject.components.signable ~= nil then
            return act.invobject.components.signable:Sign(target)
       
        else
            return 
        end
    end
end

AddAction(SIGN)

local sign_handler = ActionHandler(SIGN, "doshortaction")
AddStategraphActionHandler("wilson", sign_handler)
AddStategraphActionHandler("wilson_client", sign_handler)

This code doesn't crash, but I still can't get the action to work
these are the other files that I think are relevant:

elf_paperwork.lua
signable.lua

basically, I want the paperwork to function similarly to a blueprint, but instead of getting a recipe, the user gets a tag. Right now the paperwork is examinable but not signable

Edited January 16, 2021 by MF99K