If you're using the Fediverse's reading platform BookWyrm, here's how to transfer your data from Goodreads, LibraryThing, StoryGraph, OpenLibrary or Calibre:
(If you've never heard of BookWyrm, it's like the Fediverse's alternative to Amazon's Goodreads. Here's more info about it: https://fedi.tips/bookwyrm-a-social-network-for-people-who-enjoy-reading)