In threads app, I clicked over to the profile tab (or, my account page, idk)
Two unequal lines in the top corner (wtf, why isn’t it a hamburger menu-icon),
Took me to a page called “<- Settings” (oh, uh, not sure how I got here without a gear icon; am I old now),
Clicked down to “Account”
And there should be an option, “Fediverse sharing beta”

Am US based though. I’m not sure how meta filtered accounts they opened that feature to, if you don’t have it.