This article explains how to set up Touché or Touché SE to work within Apple GarageBand.
GarageBand scans its default folder for AU plug-ins on every launch. This folder contains the file Lié.component. GarageBand doesn't feature a Plug-in Manager for configuring your plug-in database.
When it comes to MIDI devices, GarageBand is fully integrated with the Audio MIDI Setup of macOS. This is why there is no need for an extra panel inside Logic, in order to activate the MIDI input of Touché (SE) manually.
For more information on the subject, read this external article from Apple: Set up MIDI devices using Audio MIDI Setup on Mac
The controller data coming from Touché (SE) and controlling the parameters in Lié will always be recorded as automation written inside and linked to the specific MIDI region.
You can quickly step through the Automation Lanes with a dedicated button called 'Automation Cycle Through' button, directly next to the field where you choose the Controller.
For older versions of GarageBand, the feature of editing automation data within regions was still called "MIDI Draw" - read this external article from Apple: GarageBand for Mac: Edit controller information with MIDI Draw