Splice Bridge (beta) is supported in Logic Pro 10.4+ 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: [link to Installing Splice Bridge article]
Then, add a new Software Instrument track. Under "Details," select "An Instrument Plug-in." Under "Instrument," select AU Instruments > Splice > SpliceBridge > Stereo.
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 Logic Pro.
When you find a sample you like, simply drag and drop it from the Splice Desktop App into Logic Pro.