Go to C:\inetpub\wwwroot\pam\idp and edit file appsettings.json:

Section IdentitySettings 

• DirectoryMechanism — Mechanism of authentication.

• Authentication —  Authentication provider.

  "IdentitySettings": { ... "DirectoryMechanism": "Radius", "Authentication": "Local", ... }

  
  

Section Radius

• AuthenticationScheme — authentication scheme in radius. Possible parameters: PAP, CHAP, MSCHAPV2. The PAP scheme is insecure.

  Using CHAP authentication in windows, it is necessary to enable "Store passwords using reversible encryption" in the user account settings and update the user's password.

  
  

• AuthenticationUserName — name format for authentication.
  • Possible parameters:
    • NameWithoutDomain — name without domain (for authentication in FreeRadius)
    • SamCompatibleName — name in the format INDEED\\user
    • PrincipalName — name in the format user@indeed.domain
• Secret — secret for the additional authentication of the component.
• Timeout — timeout waiting for a radius server response.
• RemoteEndpoint: 
  • Address — radius server address for connection.

  • Port — radius server port for connection (default port: 1812).

    "Radius": { "AuthenticationScheme": "MSCHAPV2", "AuthenticationUserName": "PrincipalName", "Secret":"ENCRYPTED_CfDJ8MPJ7V58kgpLvtoHgdiuk5VKMK_hf3r437uZdHjdZAfve5wtVvgDZPjjDm7bgjCXKM5XM", "Timeout": 10, "RemoteEndpoint": { "Address": "PAM_RADIUS_SERVER", "Port": 1812 }