How a call supplies the provider's credentials. All optional: with none, the provider uses its
own environment fallback, as every Communication call does. A stored credential (an
MJ: Credentials row) is decrypted through CredentialEngine, so a scheduled sync needs no code
that holds secrets; its values are used alone, with the environment fallback off.
How a call supplies the provider's credentials. All optional: with none, the provider uses its own environment fallback, as every Communication call does. A stored credential (an
MJ: Credentialsrow) is decrypted through CredentialEngine, so a scheduled sync needs no code that holds secrets; its values are used alone, with the environment fallback off.