Hi @remy383 ,
I am not exactly sure if I’ve understood the problem clearly.
Did you add attributes to your products as mentioned in this documentation but they are not showing in the additional details page?
I tried to check your site https://maceplast-zone.shop/plaques/ but it is showing under construction.
Please make the page public or provide a screenshot where you expect to see the attributes so that we can understand the problem better. You can use https://snipboard.io/ to share a screenshot.
Thank you.