Capacitor File Dialog

Hi everyone,
I’m looking for a solution to open a File Picker/File Dialog on Web, iOS, Android.

The Capacitor Filesystem Plugin is not opening a Dialog on the Systems. Therefore I was looking for Cordova plugins. File Picker and File Chooser can be used for iOS and Android, but somehow I’m not able to get them to work. On Web I would just use Angular Solutions for that.

I’m on Ionic v4.

What is the valid solution ?
Any example sources ?
How should I manage that ?

Thank you for your time and help!