Subscribes an endpoint to an Amazon SNS topic. If the endpoint type is HTTP/S or email, or
if the endpoint and the topic are not in the same Amazon Web Services account, the endpoint owner must
ConfirmSubscription action to confirm the subscription.
You call the
ConfirmSubscription action with the token from the
subscription response. Confirmation tokens are valid for three days.
This action is throttled at 100 transactions per second (TPS).