Free and priced order tags by quantity?

Hi Devs, I am trying to implement SambaPos in my Pancake house, as i am facing some troubles to do it i am here to ask for the best solution to my problem.
I have one item named Crepe Siuço, wich has two free complements and adittional cost $2. I need a guide how to do it with actions and rules. it looks so simple and i cant do.

Did you see that post?

Hi @emre, i see that post but i believe is not that i need, i ve already configurate that part of the program, my product crepe has 20 order tags that client can choose as flavours such as: ham, cheese, chocolate, bananas, etc.priced as free. Client can choose 3 for free and additionals must be paid.
I think what i need is somthing like this: Extra Option to include order tag quantity in Max Selected Items
But i cant understand how do i implament this.