Hi again,
It looks like you are using the wrong functionality of this plugin.
This is a function that allows to select additional options attached, and so it can select multiple options at the same time.
The function you want is to select a quantity to purchase, so you have to use Woocommerce’s variation product function to display it.
Please check demo, I have just create new product with variation option” https://www.tourigalo.pt/produto/carne-de-porco-assada-demo/
Or another way, you specify porção = 200gr, we will have the option to choose the quantity: 2,3,4,5 … also equivalent to the options you want customers to choose