[Xrystal]

This is code I got from the official action button file and incorporated into my own button.

-- Get the binding key ( if any ) for this button and display it
    local key = GetBindingKey("CLICK "..DFMB:GetName()..":LeftButton")
    local text = GetBindingText(key, 1)
    if ( text == "" ) then
        DFMB.HotKey:Hide()
    else
        DFMB.HotKey:SetText(text)
        DFMB.HotKey:Show()
    end

This is the part of the official code I based it on.
https://github.com/Gethe/wow-ui-sour...utton.lua#L453

Hopefully it will help see where you might be going wrong. Because my button isn't based on a Blizzard template ( it doesn't have to be a secure frame ) I had to set up the related Binding information such as a localized global string and a Bindings.xml file set up with the binding key chosen by the player.