Replo works out of the box with any properly configured Shopify analytics. If you want to  capture custom parameters for events sent to Meta Pixel you can do so using a custom javascript interaction on Replo.

1. Add an interaction to the button you want to log an event from, in this example we'll use the On click event, and then choose "Run Javascript"
   
2. (Optional) Use Meta's event setup tool here to help construct your javascript
3. Click "Launch Editor" and then enter your custom javascript in the editor, and click save code.