In order to take advantage of Chatcast's List Import feature, you'll need to make a one-time purchase Facebook's Customer matching API. You'll need to pay $99 for each Facebook Page that uses Customer Matching. NOTE: your pages must be based in the USA for this feature, only USA phone numbers will be matched as of 10/20/17
1) Navigate to your Settings tab on your page.
2) Navigate to Messenger Platform
3) Confirm page is based in US and click Make Payment