Thats great to hear Axel!
Best of luck with your project.
Yes, you can use GameSparks to upload images and share it with your players.
I've linked two tutorial below on how you can achieve this.
Let us know if you need anything else.
Sean
https://docs.gamesparks.com/tutorials/database-access-and-cloud-storage/uploading-binary-content-from-game.html
https://docs.gamesparks.com/tutorials/game-engine-integrations/unity-uploading-and-retrieving-images.html
Axel Dabee