Why is my crowntail male betta fish not eating?

I just got him today and when i was feeding both of my fish, I put the food in his bowl and he reacted like there wasnt even food in his bowl. Im not used to this bc my goldfish, Dr. Phil (yeah thats his name lol) always eats every flake i give him. Even from the start when I first got Dr. Phil he always ate all his food. I am using goldfish food for my goldfish, and betta fish food for my betta fish. The brand of my betta fishes food is called "Tetra O BettaMin Tropical Medley With color Enhancers" Is the reason he's not eating bc it is the wrong food type or what? Plz help!