General support in using @channel, @here or date formatting with slack can be found here.

Slack Authentication

Upon Creating the Connector Auth in Locoia, you will be taken to a screen to authenticate your Slack space:

Slack Webhook Trigger

Formatting Messages

In order to format messages, check out this article from Slack.
The most common request will be sending html links, which can be done like (copied from Slack's docs):
<|This message *is* a link>