Eating food after a fly lands on it is not recommended because flies land on poop and other trash before landing on your food.
But I have eaten food myself before several times after a fly has landed in or on it and I just removed the fly or flies and then continued to eat the food.
I have never gotten sick from eating food after a fly lands on it but if it were a food establishment serving the food and a fly landed in the food then they would have to throw the food out.
But for me it has never been a problem to just remove the fly and continue to eat the food.
I've also had flies land in my drinks and I just remove the fly and continue drinking it and I've also swallowed flies before in drinks.
Never gotten sick from it.
So I wouldn't worry too much and just remove the fly and continue eating your food.