Optionalcallback_Optionalchannel_Additional identifier set by the channel that represents a specific id used by the channel.
Optionalcredential_The ordinal number of the credential. This field is used when the application supports multiple credential integrations per channel. Currently, this is only applicable to the LINE channel. For other channels, this value will always be set to 0. In the case in which there are multiple credential integrations per channel on a single app, this field must have a unique value for each multi-credential channel entry.
OptionalstateThe state of the channel credentials integration. When a channel is activated, the user is prompted for credentials that must be validated and in some cases exchanged by a long-lived token (Instagram).
The secret used to verify the channel callbacks for channels which support callback verification. The callback verification is not needed for Sinch-managed channels because the callbacks are not leaving Sinch internal networks. Max length is 256 characters. Note: leaving channel_callback_secret empty for channels with callback verification will disable the verification.