TypeError: leaderboard.getConnectedScores is not a function

[kavin404]

I am trying to invoke getConnectedScores method in facebook instant games plugin in phaser

 this.facebook.once('getleaderboard', function (leaderboard) {
            this.leaderboard = leaderboard;

            console.log(leaderboard);

            leaderboard.getPlayerScore();
            this.leaderboard.on('getconnectedscores', function (score) {
                console.log(score);
            }, this);

            this.leaderboard.getConnectedScores();
          
}, this);


this.facebook.getLeaderboard('Omi-game');