Edit Json Product Templates to Sell In Multiples or Steps of 12

[rachelb5499]

I just updated to the Refresh Theme. I figured out how to add more product templates, but I'm stuck.

I have my default product template that I want to leave just as is, but I made two more templates. I'd like THOSE two new templates to change the quantity selector to sell in multiples or steps of 12.

I've searched as much as I can, but I can't find a simple solution to edit JUST Those two templates so all of my other products just sell/can be added to the cart in multiples or steps of 1 while my custom products/templates sell in multiples or steps of 12.

I've tried a variety of apps and they all slow down my website loading speed, have flaws/issues, or are way too costly per month so I haven't even tried them. Does anyone have an easy tutorial/way to show me how to edit code on these two produ