1. Make sure you've installed Hex FX, as per the Installation guide
2. Open Ableton Live (Windows 11 & version 12.1 is used in this example)
3. Choose Options > Settings and select Plug-Ins from the Setting tabs, then enable Use VST3 Plug-In System Folders, Use VST3 Plug-In Custom Folders (if you've chosen a custom plug-in installation location), or Use Audio Units (for macOS users only):
   
4. Create an Audio, MIDI, or Return track, then select Library > Plug-Ins > Serato from the Browser Content Pane, and drag Hex FX onto the Drag Audio Effects Here panel:
   

If you’re using Hex FX for the first time, learn about activation or starting a trial.