How to send Errors notifications to a Slack channel

[marcosluis2186]

Hey guys. This is what I'm trying to achieve here. We are heavy users of Firebase Functions for our backend development, and we want to send a notification when any ApplicationError occurs in our functions. 

I'm using the Errors Configure Notifications tool:

Then, I configured the Notifications channels: Slack, Webhook, and Email 

But when I try to select the channel, is only showing Email:

Any idea how to solve this? Thanks in advance.