Any free cloud for PC and mobile?

Hello everyone.
I’m building an app on mobile AND desktop where I have to share a save file.
I need to download the file when I start the app and upload it to the same location later (if I can connect to internet. If not, the save is local), when I press a save button.
I’m currently working with Firebase, but it seems I can’t upload the file with the desktop app, even using UnityWebRequest.

Does anyone know a free way to share a light file between my (Android) phone and my (Windows) PC ?

Hi,
There is a .NET API for Google Drive (JavaScript quickstart  |  Google Drive  |  Google for Developers) and there is also an asset on Github (GitHub - elringus/unity-google-drive: Google Drive SDK for Unity game engine), but you can use the bare C# API if you want.

Thank you for the answer.
I already tried the API from Elringus and couldn’t get it to work, probably because of the authorization credentials. I left this solution but I feel like I have to try it again because it seems a good way to do what I want.

Dropbox is one of the best known cloud storage solutions, which means you can use it to share files with others with little-to-no difficulty because almost everyone you know probably already has their own account.