Splice Bridge (beta) is supported in Ableton 10.1+ on Mac 10.14+.
Splice Bridge is currently in private beta with a limited set of Splice subscribers. If you are in the beta, check the email associated with your Splice account for instructions.
First, make sure that you have installed Splice Bridge: Getting started with Splice Bridge (beta)
Then, navigate to Ableton Preferences and ensure that you have turned on "Use Audio Units" and "Use VST3 Plug-In System Folders." These are turned off by default, so be sure to enable them so that Ableton can recognize Splice Bridge.
Then, navigate to "Plug-Ins" in the left sidebar and find "Splice Bridge" under "Audio Units" or "VST3".
Double-click Splice Bridge to create a new track with Splice Bridge. If the Splice Desktop App is open, Bridge will automatically connect.
Once Bridge is connected, any samples you select and preview in the Splice Desktop App will be routed through Bridge and played back in Ableton.
When you find a sample you like, simply drag and drop it from the Splice Desktop App into Ableton.