My first sourdough loaf ever but it came out really dense :(

I used this recipe https://preppykitchen.com/sourdough-bread/

I’m really new to this so I don’t know proper verbiage but I did let it sit in the fridge over night for about 15 hours. Before I baked it I had it sit out of the fridge for an hour and I made sure to heat the Dutch oven for an hour before baking it.

I followed the recipe exactly!