I use imgur. I make an album with the app and then copy and paste a link in the post. When you click the link it takes you to the album. Only downside is that that there aren't any thumbnail pics, but they are high resolution in the album.
Imgur has made some changes.
All you have to do to use them is copy their direct link and paste it here inline. Not coding or clicking the Image button.
That does however leave you photos in their branded frame as shown in the posts above.
If you don't want that, another hosting site to try would be https://kek.gg/
Like Imgur, there is no signup, but they appear to be more privacy oriented and do not embed you pictures in their advertisement.