I want to limit the upload of items to a database depending on the pricing plan I have active

I have a car Marketplace (www.4goma.com) wand I have a database to which vehicles are uploaded. I also have the Pricing Plans software with 3 Plans.

  1. Classic Plan: Upload up to 10 vehicles
  2. Advanced Plan: Upload up to 20 vehicles
  3. Elite Plan: upload unlimited vehicles.

I also want that when your plan is finished, the uploaded vehicles are hidden from the public.

If any of you could help me with code to achieve this functionality, I would greatly appreciate it.

You will need backend and frontend code together or a router that will do it the job. There are many ways to achieve this but only thing for sure is you will need JS knowledge and Velo APIs.

-check this also:
wix-pricing-plans-backend - Velo API Reference - Wix.com