When searching for proof and asking a question in which you can provide doubt in any scenario, a la Descartes, it is important to remember that the doubt is evident in itself in the dichotomy of the nature of your question, as well as the doubt itself, as a thing in itself. So your question, or request, isn't concerned with reality, or temporal being at all, existence just is, it has no capacity to question itself. Likewise, proving something against a doubtfulness that would be given a capacity to doubt everything would only end up of doubt itself, so it is not an argument.