Hi,
As far as I know the Société Générale only supports SIPS ATOS v1 not the v2. The v2 is supported by some belgium banks and they don't support anymore the v1.
The difference is that the APIs between the v1 and the v2 are not compatible together. So you need to use the one that is supported by your bank.
The link you posted is the one you want to follow for the Société Générale. I suppose your bank should also provide you with some kind of kit with PDFs and certificates in order to set that up on your website.