In fact, if you don't care much about the effect of cutting, then both tooth scissors and flat scissors are ok.
However, after the hair is cut with flat scissors, the hairline will be thicker, because it is best to use dental scissors. Tooth scissors can reduce the thickness of bangs, and the bangs thinned with tooth scissors will be softer and better looking.
If it's no trouble, you can also cut the bangs a little with flat scissors first, and then change your teeth.