If you don’t have buttermilk readily available at your home, you can easily make your own! Just a small process it has to make this -
Add 1 tablespoon of lemon juice or vinegar to a liquid measuring cup, then pour in milk, up to the '1 cup' mark. Mix the mixture then let it sit for 5 minutes until it curdles and thickens slightly. Then it will be ready for the bread recipe.