The less flour you use, the lighter the gnocchi will be, but the more likely it will be to go mushy while you wait to cook it, handle it and when it is cooking in the water. For a kilo of potatoes, you can use anything from 200g to 300g (from 1 2/3 to 2 1/2 cups) flour.
Find it online: https://organictuscany.org/recipes/gnocchi/