Hey @micaelamartinez
So after reviewing AddThis documentation I don’t know if a custom module will be the best implementation and possibly the issue. Rather you can add the code to the tamplate its self.
When using the drag and drop template builder, at the bottom of the Edit panel you can paste the code into “Additional markup before </body>” sections. Image below:
If using Html/Hubl templates you can just paste it inside the body tag.