Hi Serge
When you receive a HTTP 403 response, it means that the authentication is successful, yet your called system does not allow you any further. It’s an authorization issue from the telephone server you’re trying to call, I believe. Or you had to indeed update the credentials with new ones – as you described yourself.
If the issue no longer persists, I believe updating the subscription did the trick. How long does this subscription stand? Can you get more information from your telephone server?
Kind regards,
Leander