Buckwheat is a grain…. I don’t understand how this bread …

Name: How to Make Grain-Free Bread
Prep time: 30 min
Cook time: 1 h
Total time: 1 h 30 min
Cuisine: Plant-Based
Ingredients: 1 cup organic green banana flour (100g); 3/4 cup light buckwheat flour (75g); 3/4 cup seed/nut flour*(65g); 1/2 cup tiger nut flour (60g); 1/2 cup arrowroot starch (50g); 2 tablespoons whole psyllium husk (14g); 1 tablespoon coconut palm sugar; 1/2 tablespoon sea salt; 1-3/4 cups water, room temp. (420g); 2 tablespoons GF baking powder**