Some friendly but direct advice (as I've wanted a clear and up-front shrinkflation evidence website forever): if your goal is to get people to contribute examples, then those landing pages are failures.

The first link reads like it's basically nothing. No content. A single photo of ancient sardines with no caption or purpose. It's some backrooms internal Wiki page. "Possible uses" like you're not even sure what you're doing. Your first sentence makes no sense: "Log on Open Food Facts food products that are not sold anymore and were on sale there..." That's gibberish. "Where to find the products"? What products? What? What is this page?

I'm not trying to be rude, just give you a chance to hear how it reads to a user unfamiliar with what you're doing, looking at it whatever that is for the first time.

The second page is dominated by a donation banner, and it's already a hard sell to get someone to download an app. What I gather from the first graphic is that this is a carbon-neutral, EU effort to get me to eat bugs or soy paste. The graphic literally means I have to weigh my personal enjoyment with someone's conception of what's best for the planet at large (and historically that's meant things like "you will own nothing and you will be happy").