SAML between FORTIGATE 400F FORTIAUTHENTICATOR AND FORTIPAM 1.5

Hi support, 

am currently preparing the deployment of FortiPAM for SSL VPN access. Today, users authenticate with username + password + a token generated by FortiAuthenticator. FortiPAM is also integrated with the FortiAuthenticator.

My question is: how can I change the configuration so that when a user connects through the SSL VPN (username + password + token), the authentication is redirected to FortiPAM, and once inside FortiPAM, the user is not asked to enter the token again since they are already authenticated through FortiAuthenticator?

Br