Icinga2 notification just once on state change - icinga2

Question

I have set up icinga2 to monitor a few services with different intervals, so one service might be checked every 10 seconds. If it gives a critical error I will receive a notification, but I will receive it every 10 seconds if the error persists, or until I acknowledge it. I just want to receive it once for each state change. Then maybe after a specified time again, but it is not that important.
Here is my config:
This is more or less the standard template.conf, but I have added the "interval=0s", because I read that it should prevent notifications from being sent multiple times.
template Notification "mail-service-notification" {
command = "mail-service-notification"
interval = 0s
states = [ OK, Critical ]
types = [ Problem, Acknowledgement, Recovery, Custom,
FlappingStart, FlappingEnd,
DowntimeStart, DowntimeEnd, DowntimeRemoved ]
vars += {
notification_logtosyslog = false
}
period = "24x7"
}
And here is the part of the notification.conf that includes the template:
object NotificationCommand "telegram-service-notification" {
import "plugin-notification-command"
command = [ SysconfDir + "/icinga2/scripts/telegram-service-notification.sh" ]
env = {
NOTIFICATIONTYPE = "$notification.type$"
SERVICEDESC = "$service.name$"
HOSTNAME = "$host.name$"
HOSTALIAS = "$host.display_name$"
HOSTADDRESS = "$address$"
SERVICESTATE = "$service.state$"
LONGDATETIME = "$icinga.long_date_time$"
SERVICEOUTPUT = "$service.output$"
NOTIFICATIONAUTHORNAME = "$notification.author$"
NOTIFICATIONCOMMENT = "$notification.comment$"
HOSTDISPLAYNAME = "$host.display_name$"
SERVICEDISPLAYNAME = "$service.display_name$"
TELEGRAM_BOT_TOKEN = TelegramBotToken
TELEGRAM_CHAT_ID = "$user.vars.telegram_chat_id$"
}
}
apply Notification "telegram-icingaadmin" to Service {
import "mail-service-notification"
command = "telegram-service-notification"
user_groups = [ "icingaadmins" ]
assign where host.name
}

Answer 1

I think you had a typo.
It should work if you set interval = 0 (not "interval = 0s")
After that change you must restart the icinga service.