Checkout only if divisible by X

Hi there. We are currently creating a Shopify Store for a Winery. Due to packaging, handling and also ecologic reasons, the final package should always consist of a quantity that is divisible by 6.

As Shopify Support is not of any help to a solution here, i would like to ask the community if anybody was facing the same problem and was able to solve it. We would prefer a working APP over coding…

Following use case given:

  1. I add 5 bottles (same or different products) to my shopping cart
  2. I go to my shopping cart via the shopping cart button
  3. I see the following message in the shopping cart “Due to economic and ecologic reasons we only ship packages with a quantity of bottles divisible by 6. Please add or remove products accordingly (e.g. 6,12,24,..)*”
  4. I ignore the hint and click on “Checkout” or “Express Checkout”.

→ No redirection to the checkout. A popup appears with wine note “Due to economic and ecologic reasons we only ship packages with a quantity of bottles divisible by 6. Please add or remove products accordingly (e.g. 6,12,24,..)*”

Thanks in advance for any advice!

This is a very unique use case so I don’t think there is an app that tackles this.

I am afraid it would have to be some custom coding that would disable the checkout button when the total product count isn’t divisible by 6.