This error mainly comes because of the below thing.
1. Server URLs does not match.
Make sure that the “Server URLs – Used for Web SDK” matches with the one where you’re using Digits.
Go to your Facebook app on https://developers.facebook.com then navigate to Account Kit (Present on the left hand pane) -> Web Login Settings (You’ll need to scroll) -> Server URLs – Used for Web SDK
Check if the domain(s) provided there matches with the one(s) on which Digits is installed.
Pro Tip: Provide both http and https version of your root domains there.
If you are using Firebase as your gateway and you get this error then the issue is because the site url you mentioned in Firebase setting does not match with the one you are using the plugin on.
So make sure that your site url matches with the one entered in Firebase console settings
If you are getting Google Captcha when requesting for OTP then its very sure that you are using “Firebase” as the SMS gateway. So as per Google’s requirement for Firebase, its not possible to remove that captcha, we have no control over it and it is totally handled from the Google Firebase’s side.
This means you are using Account Kit as your SMS gateway, as per their requirement there is no way to have the verification on the same page (just for this gateway).
So if you dont want to have this, then you can use any other SMS gateway including Firebase (Free). All other gateways will perform the verification on the same page and in the same form.
Make sure that you’ve entered Facebook <strong>Account Kit API </strong>not the Facebook Application one. As this is the most common issue. 😛
Check if the “Anyone can register” is enabled under Settings -> General , if not please enable it.
If you have WooCommerce installed make sure “Enable customer registration on the My account page.” is checked under Woocommerce -> Settings -> Accounts, otherwise the registration option will not come on your “My Account Page”
Please open the below link to get answers to all of your questions relating to Facebook Account Kit