Product quantity based on user input

Hello there,

I would like to be able to determine the quantity of products added to cart based on user input. My example scenario is as follows:

– User opens product
– User ticks 2 x checkboxes of children’s names they would like to buy their product for (this is already linked to their account)
– When the user hits ‘Add to basket’, 2 of those products are bought with the children’s names against them.

The linked tutorial helps, but my main question is: how do I add the quantity to basket based on user input?

Thanks for your help

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