Separate or one authentication for realtime and chat?

Hello,

I would like to ask do need to separately authenticate photon realtime and photon chat or both are done using this:

private void RequestPhotonToken(PFLoginResult result)
    {
        Debug.Log("PlayFab authenticated. Requesting photon token...");

        _playFabPlayerId = result.PlayFabId;

        PlayFabClientAPI.GetPhotonAuthenticationToken(new GetPhotonAuthenticationTokenRequest()
        {
            PhotonApplicationId = PhotonNetwork.PhotonServerSettings.AppID
        }, AuthenticateWithPhoton, OnPlayFabError);
    }

    private void AuthenticateWithPhoton(GetPhotonAuthenticationTokenResult obj)
    {
        Debug.Log("Photon token acquired: " + obj.PhotonCustomAuthenticationToken + "  Authentication complete.");

        var customAuth = new AuthenticationValues { AuthType = CustomAuthenticationType.Custom };
        
        customAuth.AddAuthParameter("username", _playFabPlayerId);    // expected by PlayFab custom auth service       

        customAuth.AddAuthParameter("token", obj.PhotonCustomAuthenticationToken);

        PhotonNetwork.AuthValues = customAuth;

    }

Also if needs separate authentication please guide me through that.

I would like to ask one more thing, since I have created another application for chat in photon dashboard, do I have to set custom server authentication for chat application too or only setting in photon realtime application is enough.