Picking a Photo from the Picture Library

I devs !

I must pick photo from the Picture Library and send them to a ftp server.
I used this link for help me : https://docs.microsoft.com/fr-fr/xamarin/xamarin-forms/app-fundamentals/dependency-service/photo-picker.

I must create a thumb from the photo (no problem) and store the path...
How can I return two informations to the shared code ? I use then Android implementation for the specific code.

Thx