Update product variant quantity automatically after other variant runs out of stock

Hello all

I am using Wix Stores to equipment rentals. I know that Wix doesn’t have a specific tool for this at the moment, and for that reason I am trying to solve this problem using the Corvid.

The thing is:

  • 1 product with two “variants”: (1) 15 days period and (2) 30 days period.
  • I put the quantity for both variant to 1
  • However, the “physical” product is only one and, therefore, when someone rents the 15-day period variant (quantity = 0), I need the 30-day period to be updated to quantity = 0 also.

Attached is what I tried so far, which is not working. (For some reason I could not paste it here)

Any clues?
Thank you!