I have a question. How can I really figure out whether my (static) website uses http2? The google audit tells me that I should use http2 for all of my resources

I have a question. How can I really figure out whether my (static) website uses http2? The google audit tells me that I should use http2 for all of my resources but loading my site in Safari or Chrome shows me that it uses the h2 protocol. Or are these unrelated? Weirdly it also points out that my elements have non-unique Ids which is false and the list of failing elements shows that, it looks like they are stopping their search at the colon character, but they should not.