To browse presets for Astra, navigate to the "Presets" tab from the Sounds homepage. From there, you can choose an instrument type to narrow down your search, or browse all Astra presets.
When you've found a preset you like, click the download button to add it to your library:
If the Splice desktop app is running, the preset will sync to the presets section in the app:
These presets will automatically download to Astra's preset folder. Depending on whether you're on Mac or PC, Astra presets will download to one of these locations:
Mac: Macintosh HD/Users/[your username]/Library/Application Support/Splice/Astra/Presets/Splice/From Splice
Win: C:\Users\[your username]\AppData\Splice\Astra\Presets\From Splice
This means it will also show up in Astra's preset browser automatically - you don't need to do anything else to start using your downloaded presets in Astra.
You can open them up through the "from Splice" folder in Astra's preset browser: