They simply make use of FB‘s Marketing APIs, which are well documented: https://developers.facebook.com/docs/marketing-api/audiences-api https://developers.fac

They simply make use of FB‘s Marketing APIs, which are well documented: https://developers.facebook.com/docs/marketing-api/audiences-api https://developers.facebook.com/docs/marketing-api/audiences... https://developers.facebook.com/docs/marketing-api/reference/custom-audience https://developers.facebook.com/docs/marketing-api/reference... https://developers.facebook.com/docs/marketing-api/buying-api/targeting https://developers.facebook.com/docs/marketing-api/buying-ap... https://developers.facebook.com/docs/marketing-api/targeting-search https://developers.facebook.com/docs/marketing-api/targeting...