I've tried this:
there are a lot of free (animated) gifs available, e.g. under
https://www.freegifs.de/animierte-gifs/autos/gifs-autos.html (the nice Porsche 911, turning).
Under "Android" you get, amongst other options, the option "safe picture" when tapping on the animated picture (press and hold). In other OS this migt be a "rightclick" on the picture (the animated *. gif file). Chosing this option downloads the animated *.gif, usually into the "Download" folder.
From there you can attach it to your post, as you can see below.
Test environment:
Samsung tablet SM-T555, Android 7.7.1
(I know, everything quite historic

)
Firefox (internet browser).
But can anybody help me, how I can embed pictures from the BEA, e.g. the nice morphs from Captain Nemo? (Thanks Capt'n for allowing me to do so

)
The procedure above didn't work because either I get a *.bin file or a *.php file downloaded, which, when attached to my post doesn't show anything (which I can understand from a technical standpoint of course)?