I know that it is possible to create a FeedItem using Flow (as I have done so!), but is it possible to create an @mention in the body of that FeedItem?

I have tried doing @[{!varManagerName}], as well as using just the Id and another number of combinations, but it doesn't seem to want to work :)

If someone can help me figure it out, I would be ecstatic. This would be an absolutely perfect solution to a process issue we are currently experiencing!