Filepicker for external services


I was wondering if there exists any filepicker for Nextcloud that can be used by an external service.

By a file picker I mean like the File to share window from Chat where you get an overview of your file system and can navigate through it and pick a file just as you can from Files itself.

When I say external service I mean from outside Nextcloud. This is similar to what for example OneDrive have, where a popup type window open up and let the user authorize, then navigate through a filepicker.

Iā€™m trying to see if there are any currently available solutions for this.

Thank you for your time.