I tried it. The Flare can connect to Google (maybe also Siri but I've no way to test that). Not to Alexa. The one I actually use and is a market leader.
No beans on the Soundcore and no option to even try it on the Soundcore Sport.
I have a Samsung GS7, which some people are apparently going to call an unusual phone despite its ubiquity.
So again, among the Anker speakers I own, this is not available on most. Maybe it is on the ones you own. It won't connect to the only voice assistant I use on the speakers that do offer it if you have a Samsung phone, which is not an unusual Android brand of phone or an unusual phone.