Renotification not triggered from icinga

I have setup slack notification for my service check. But it triggers notification only once when it goes from OK to Critical or Critical to OK.
I have kept check_inerval to 5 min and retry_interval to 5 min. In Icinga console I see alert is tried and processed again after 5 min but I don’t get a notification after each attempt.

Also i see in my master/slack.cinf i see below so looks like reattempt is not going to work. Can I trigger renotification for specific service?

template Notification “slack” {
command = “slack”
interval = 0