English Translation
I want you to make me a promise.
*hagas??
I want you to make me a promise.
*hagas??
My spanish is super rusty, but I think this is “ustedes” level politeness. I.e. polite plural. More specifically, 3rd person plural subjunctive.
Any of haga/hagas/hagan/hagáis would work, depending on number and degree of formality. If you’re a Pro subscriber, you can add a hint saying “ustedes”. Alternatively you can make it a habit to enumerate all possible forms before answering, so you won’t be surprised.