pub async fn create_user_defined_message_subscription(
configuration: &Configuration,
account_sid: &str,
call_sid: &str,
callback: &str,
method: &str,
idempotency_key: Option<&str>,
) -> Result<ApiPeriodV2010PeriodAccountPeriodCallPeriodUserDefinedMessageSubscription, Error<CreateUserDefinedMessageSubscriptionError>>Expand description
Subscribe to User Defined Messages for a given Call SID.