That makes absolutely no sense. If you claim something exists, you have the job of providing evidence for that existence. If I am simply asking whether you have a proof, I am not making a statement at all. I am simply asking if you actually have proof of your claim.
Now, if I was actually claiming that no God exists, you would have a point: you could legitimately ask me to prove my position. But that is not the case. YOU make the existence claim. It is YOUR job to prove it.
Asking for proof is not a claim you are wrong: it is an investigation as to your reasons for thinking what you do.
There are too many different ideas about what the word 'God' means to deal with all of them.
For example, if you define God to be 'the universe', then I believe God exists. But I also think that this would be an abuse of language.
Part of asking for a proof is also seeing what you mean by the term 'God' and what it takes to show existence of non-existence. if the concept is too vague, then there is no real discussion possible.
I disagree. When the HIgg's particle was proposed, it was NOT the job of those who thought it didn't exist to *prove* it didn't exist. It was the job of those claiming it does to prove it. That burden of proof is universal, but you seem to want to dodge it because you know there is no proof of the existence of your deity.
I'll tell you what. YOU give me an observation that could be made and that, if it doesn't go the way you expect, would convince you that your God does not exist. Then we can go and do the observation.