Hello!
So I have been trying to solve this for a little while now, but what I found just wasn't working.
I can't post pictures on forums? When I click the little picture button and put in what it says to, the image doesn't appear. Also tried the code way and that did not work either.
I looked to this post for help, but it did not work: https://toyhou.se/~forums/thread/7615.how-do-i-add-images-to-threads-/0
Did you use the correct link for the picture you wanted to insert? If you use the page link shown in the URL bar you haven't specified which image you'd like to show up and it will fail. If you copy the link off of the image itself by right clicking and choosing 'copy image link' it should work.
If that doesn't solve the issue, could you show the HTML code you're using when it fails?