To add Bridge to Logic Pro, first, make sure that you have installed Splice Bridge via the Apps & Plug-ins section of the Splice desktop application.

Make sure you have installed the component (AU) version of the Bridge plugin, as Logic isn't compatible with VST3 plugins.

Then, add a new Software Instrument track to your project in Logic. 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 you've added it to a MIDI track in Logic:

For more information on using Bridge with Logic once it's been installed, check out this article: How to use Splice Bridge