JWTAuth.cs

//AppHost.cs, Configure method
 AuthFeature authFeature = new AuthFeature(() => new UserSession(), new IAuthProvider[] {
    container.Resolve<IAuthProvider>(),
    new JwtAuthProvider(AppSettings) //=> use DI to register
    {
        AuthKeyBase64 = ConfigurationManager.AppSettings["jwt.AuthKeyBase64"],
        RequireSecureConnection = false, //dev configuration
        EncryptPayload = false, //dev configuration
        HashAlgorithm = "HS256"
    }
});

//Add two properties in your custom session class
public class UserSession
{
    //...
    public string BearerToken { get; set; }
    public string RefreshToken { get;set; }
}
//in OnAuthenticated method, appSession is UserSession object
JwtAuthProvider tokenProvider = new JwtAuthProvider(); //=> use DI to resolve
appSession.BearerToken = tokenProvider.CreateJwtBearerToken(session, appSession.Roles);
appSession.RefreshToken = tokenProvider.CreateJwtRefreshToken(appSession.UserAuthId);
authService.SaveSession(appSession);