Help with "helpbutton" & targets

[Stormm]

How would I replicate this using SetAttribute?

/cast [help] Flash Heal; [target=player] Flash Heal

right now this is what I am using and can't make it work.

MyButton:SetAttribute("helpbutton", "friendlytarget")
MyButton:SetAttribute("unit-friendlytarget", "target")
MyButton:SetAttribute("unit", "player")
MyButton:SetAttribute("type", "spell")
MyButton:SetAttribute("spell", "Flash Heal")

If I click my button with a friendly targeted, Flash heal goes off. If I click my button with no target, I would expect it to heal me but it doesn't.

If I comment out, MyButton:SetAttribute("unit", "player"), my cursor changes form to indicate I need to pick a target since none were defined. If I uncomment it to define it, clicking the button with no target does nothing again. What am I missing here?