We'd like to start running Facebook DPA ads when customers abandon cart.
Do we need to add any specific code to our theme to do this? Or is it enough to just put in our Facebook pixel into Online Store > Preferences > Facebook Pixel & have a linked FB Business Manager accounts with a sync'd product catalogue?
I know there had to be code added to the theme in the past but I'm not sure if it's still required.
You don't need to add any code to your theme as far as I know. Just make sure the catalog syncs with the store.