I’d recommend signing up for Imgur, uploading your images to there, and it should give you a sharable link to the images/portfolio of images you make, which you can then copy and paste onto your forum post. This method is common amongst the build team applications, as they ask for samples of builds, and most if not all of the applicants use Imgur.
Although it’s not fully server related, here’s the link to where you can sign up:
https://imgur.com
Hopefully it works. I must admit, I’m looking forward to seeing your artwork, especially as I’ve seen you post about it before.