Object(...) is not a function - FileChooser

Ionic Framework ionic-v3
1

Hello, I am trying to implement file chooser for ionic v3. But getting error Object(…) is not a function.
Here are the version details.

“cordova-plugin-filechooser”: “1.2.0”,
“ionic-angular”: “3.9.2”,
“cordova-android”: “7.1.4”,

this.fileChooser.open().then((uri) => {
      console.log(uri)})
    .catch((e:any) => {
      console.log(e);
    })

Issue1