You will have to add the respective Pixel ID in the configuration modal and the destination will be ready to get activated. You can choose which events you (don't) want to send to facebook by deselecting it.
All events that you are measuring at the point of time you activated the destination will be send by default. If you add events later on, you will have to manually add them to the list if you also want to send it to this destination.
3. Once you've added the Pixel ID you can activate the destination by clicking save & activate or through the toggle in the destination overview. ✅
4. You can test your pipeline by checking out the Facebook events manager or the Facebook Pixel Helper Chrome extension.