What’s the missing ingredient?

[Grottytoilet]

DCs had mug cake gift sets from primark as a gift from someone.
No instructions on the pack apart from microwave for 3 mins,
The mix pack is just dry ingredients….but I don’t know what’s in there as no ingredients listed on pack.
What do I add to cook them? Water, milk, egg?

I would have thought veg oil, milk and an egg would be sufficient.

If you Google "Primark Mug cake instructions" you get a link to this video. It's a proper recipe but I would assume the kit is similar and has all the dry ingredients and you just add the others

Thank you!