Migrate from Ulysses
Ulysses supports Textbundle, so it's really easy to migrate. Also, Ulysses is amazing. Shoutout to the amazing team who made it. It's powerful.
1. Export all your notes from Ulysses in Textbundle format using this
2. Import all textbundle files into Spaces.
On iOS, go to Settings > Import || On MacOS, go to File > Import