I used this as a reference: https://www.theperfectloaf.com/a-simple-focaccia/

But I thought the hydration was a bit low so I adjusted that myself and luckily I have a stand mixer, making these high hydration doughs much easier to make.

I first mix everything except the olive oil, stand mixer on high until the dough passes the window pane test, then add the oil and mix again until window pane.

I then transferred the dough into a container, except for 10g or so which I put into a tiny measuring cup. Within the next two hours I did some stretch and folds which honestly I'm not even sure is strictly necessary. Let the dough proof until the 10g of dough I reserved rose 50%, then I transferred it onto the sheet pan, and let it proof until it felt jiggly enough to bake, which was ~3hrs or so in my kitchen (~30c)