Channels and webhooks issues

[CarlosHorro]

Hi,

I'm finding problems understanding how channels and alert levels work.
As Slack income webhooks (configured via vars.slack_notifications_webhook_url) are implicitly directed to one specific channel, what is the purpose of the variable vars.slack_notifications_channel ?
As an example, in order to send alerts to different channels depending on if I'm having a service-related or a host-related issue, I configured differently vars.slack_notifications_webhook_url without touching at all vars.slack_notifications_channel.

On the other hand, is there any way of configuring an alert threshold? Ie, I would like to send only alerts related to critical events and not for warnings.

Greetings,
Carlos