Right, if a hypothetical deity exists outside of the universe and does not affect it in any way, that entity would be impossible to detect, by definition. (That entity would also be irrelevant to humans.)
You might also be interested in the term agnostic:
a person who believes that nothing is known or can be known of the existence or nature of God or of anything beyond material phenomena
Some agnostics believe in a god and some don’t, what they agree on is that the truth of it cannot be known.
Agnosticism is also scientific in nature, because it acknowledges that there are no experimental ways to test the existence of a god.
And no worries, I didn’t read any hostility in your comments. I enjoy talking about this since I’ve spent multiple decades going over the topic myself.