A test authorization for vps12001.serveur-vps.net to the Let's Encrypt staging service has revealed issues that may prevent any certificate for this domain being issued.
Fetching http://vps12001.serveur-vps.net/.well-known/acme-challenge/6X5thY8iX_pUL3hnvSSrCyXlRc01UXc_ys6cZlt1haU: Timeout during connect (likely firewall problem)