Outta Bass has local and cloud presets. Cloud presets must be installed locally before they can be used.
Presets can be exported to a file to transfer between devices. These get written to your iCloud Drive.
The entire preset database can be backed up via iTunes. Its is recommended Outta Bass is not running at the time.
If you want to share a preset with the world you can upload it to the cloud library. Presets will be reviewed and if selected made available in a few days.