Tap the account switcher in the top left corner and you should see the option.
See my comment for a screenshot. I don’t know why I can’t seem to post a screenshot in the body of post. Every time I try it gets removed.
Except for the years of development the dev has a track record for developing the same thing but for reddit. /s
I don’t think the hesitation is with the developer of Sync. I think he is worried about the sustained success from Lemmy. If people keep staying active, more people will join. But it could also fade away quickly (I hope not).