liff_ isApiAvailable.js

      if (liff.isApiAvailable('shareTargetPicker')) {
        liff.shareTargetPicker([{
          type: "text",
          text: message
        }])
        .then(
          //alert("ShareTargetPicker was launched")
        ).catch(function(res) {
          //alert("Failed to launch ShareTargetPicker")
        })
      } 
      else {
        alert("你的 LINE App 暫時不支援 Share Target Picker ，將開始外部瀏覽器。")
        liff.openWindow({
          url: "{{.LIFFRedirectURL}}",
          external: true
        });
      }
    });