laffin_boy some of them seem to work at https://birdbrains.freeflarum.com/d/16, but not all of them. I believe that the extension is not fully compatible with the rich text extension (as is stated in rich text README):
BBCodes will not be WYSIWYD’ed. However, symbols used for them shouldn’t be escaped so you should still be able to use them.
Note that if you copy something and paste it into the rich text editor, it will retain the formatting. In my case for example, when copying the BBCodes from the codeblock itself, it retained the codeblock formatting which made the BBCode not render properly. You need to ensure that the text is not formatted for them to render properly (edit my post at your forum to see how you can use them)
