Why my Show HN does not appear

It got hit by a spam filter. Sorry about that; those are tuned more aggressively for new accounts. We've marked your account legit so it won't happen again. In the future, please email hn@ycombinator.com instead of posting such questions here. That's in the site guidelines: https://news.ycombinator.com/newsguidelines.html.

Since HN is an English-language site, we generally don't allow submissions in other languages (even la belle langue, I'm afraid). But a Show HN is a different case. You can post your site as a Show HN, where the intention is to gather feedback from the community, as long as the discussion is in English. But a bit more initial context will be needed. The way to do this is to add a comment to the thread giving the backstory of how you came to work on this, and explaining what's different about it. That tends to nudge discussion in a good direction to begin with, and in your case it will also make it clear to the readers that they can discuss the project with you in English.

Brand new account might need a 'vouch', another older HN to click a link.

http://vegcheck.co/ is a french website so HN might be the wrong target audience and nobody clicked.