For Voyager iOS:

Settings > General > Autoplay GIFs/Videos

Embedded a gif of how to find it (just kidding):

But which client are you using? Or maybe the web?

PS: sorry to distract, hope you can find it cuz I’m all in on embeds - folks come to scroll not to click ;)

Also on browser I’m imagining a potential Ublock Origin solution in case Lemmy doesn’t have a setting there on web