To clarify -- the below feature lets you use the same credentials for PixelFed to create a new PixelFed account, importing your avatar, bio and followed accounts.
ORIGINAL:
Apparently, it is possible to use one's Mastodon account to log into Pixelfed. Is it possible to do that with Bookwyrm and Peertube? I'd like to have a seamless login instead of having to create separate accounts for each service I want to use: