You can get a free account on Flickr to test it first. They used to be quite generous in past, but idk how much storage you get with the free account now. The embedding is a bit tricky, there is a embed feature under sharing, but for posting on Hive it doesn't work since here it is not supported. My hack for it is to go to download, select 'all sizes' then tap the image to show in a separate tab. On that tab, copy the URL (it ends with .jpg), voila.