Where are the add to cart form settings? Im just trying to find the settings page for the add to cart form. I cant find it...

Im trying to change the setting when someone adds the same item to the cart twice it will combine it into one line item, rather than creating to separate line items as it is doing now.

I have attempted to add the setting here:

but no luck. still getting multiple line items.
Turn on the Combine options in your Line Item displays and Product displays.

If you use Commerce lisense module please check this issue Commerce license does not combine line items

If not I guess this link can be helpful , you will find example of hook_commerce_cart_product_comparison_properties_alter()