Is it possible to upload an image into a post?

Just post the image link; most work.

If you want to directly copy from google, make sure to click 'view image' and right clock on that and 'copy image address' do not copy the massive google address.

Use any website that you can upload images to then post the ULR in the post. I recommend imgur.

It used to be a feature but Riot removed it as there's no real need for it. I highly doubt it will return.

There are numerous websites you can upload images to and link them here, like everyone else does.