Social sharing on Standalone build

TLDR;

How to share image in standalone builds?

We are mobile game development but recently making our first PC game.

We want to make a sharing button that simply share screenshot to Facebook, Twitter, Discord, and probably Reddit... It can be a public-share (no SDK and login) or a targeted friend-share (may need SDK and login).

W$$anonymous$$le there's a lot solutions in mobile, I searched and was really surprised that there seems not existing solution for PC at all...

The closest I found seems to be Facebook's Games SDK for PC, it's only on beta and we may not need all its function...

I understand most PC players can just screenshot and share manually, but it would be nice if that can be done with a button, analytics and even referral system.

Any suggestion?