How to use the modernizr.lockorientation function in modernizr

api.on('fullscreen', () => {
        if (Modernizr.lockorientation) {
          try {
            Modernizr.prefixed('lockOrientation', screen)('landscape');
          } catch (e) {
            console.warn('lockOrientation is not supported on this browser.');
            // the device does not support rotation
          }
        } else if (Modernizr.orientationlock) {
          screen.orientation.lock('landscape').catch(() => {
            console.warn('orientation.lock is not supported on this chrome.');
          });
        }
        this.applyRatio();
      });
      api.on('fullscreen-exit', () => {

api.on('fullscreen-exit', () => {
        if (Modernizr.lockorientation) {
          Modernizr.prefixed('unlockOrientation', screen)('landscape');
        } else if (Modernizr.orientationlock) {
          screen.orientation.unlock();
        }
        this.applyRatio();
      });
    });