The SIRET(French: Système d'identification du répertoire des établissements), or SIRET number, is an INSEE code which allows the geographic identification of any French establishment or business.
It is a 14 digit number consisting of the SIREN (the business identifier) and a five digit NIC code (the establishment identifier).
MWR Life's Siret number is 82532212600012.
This information can be found here https://www.societe.com/
Direct link: https://www.societe.com/societe/mwr-life-llc-825322126.html
The registry, the INSEE, or société.com are all official access points.