Hi @chrchcol,
Thanks for getting in touch. There are two issues here:
1) The FB Page associated with the Chat plugin is geo-gated. This means that users who are not logged in to Facebook, and are not in the allowed region(s), will not being able to access the Page (and the Chat plugin on your site will not load for them at all). If you’d like the Chat plugin to be available to all visitors (including those not logged in to Facebook), then any active restrictions on the Page (age or location) should be removed. This can be done by a Page admin, via the Page settings on Facebook.
2) Your domain is not whitelisted. This happens automatically when running the setup process. Please be sure that you run the plugin setup from the same domain you wish to have whitelisted (eg. if you ran the setup while the site was on a staging server, or something similar, the correct domain would not have been whitelisted). I would recommend running the setup process again from the WordPress admin dashboard, on thebestoftexas.org.
Hope this helps!
Facebook Team