Verify settings issue for facebook, app is not available

Hello, Everything worked perfectly before.

Recently we noticed that the FB login stopped working. We tried to re-verify but we see an error.

When I click verify settings for facebook, I receive this notice.

It seems unavailable. To fix this, please contact the developer of the app.

But the business account/App is verified by Facebook. Application is live enabled. API version is 13. And in general there were no problems before. You can see the screenshot.

All checks have been passed.

How to understand the reason that the application is unavailable?
Help us please

https://ibb.co/0ss2BKs

• This topic was modified 6 months, 2 weeks ago by azuborev.
• This topic was modified 6 months, 2 weeks ago by azuborev.