If you can’t get Pamela’s Pancake and Baking Mix, find something with the following (presumably in decreasing proportions) in it:-
Brown Rice Flour, White Rice Flour, Cultured Buttermilk, Natural Almond Meal, Tapioca Starch, Sweet Rice Flour, Potato Starch, Baking Powder, Baking Soda, Sea Salt, Xanthan Gum.