Create Incoming Webhooks in Slack
Before Slack can receive messages from external sources (like in this case Tripetto) you have to create and Incoming Webhook in your Slack App. How to set this up, gets very well explained in this article at the Slack website.
You only have to follow steps 1 to 3, so don't worry about step 4.
At the end of step 3 you will get a webhook URL from Slack that you'll need to use in the WordPress plugin of Tripetto.
Enable Slack notifications
Now back to the WordPress plugin of Tripetto. At the top menu bar of the form builder click
Style & settings. The Style & settings pane will show up on the left side of the form builder.
On the left side of this pane you can enable the feature
Notifications - Slack. After enabling this feature you can enter the webhook URL you got from your Slack App. This will result in a simple Slack message in the designated Slack channel when someone completes the form.
How we use Slack notifications at the office
Slack notifications are especially handy for larger teams. At Tripetto we use Slack notifications for example in all of our website forms. It enables us to keep track of all submitted forms, including a centralized archive of all submitted form data.
We've also made the internal agreement to mark each Slack notification with a
icon when you've read the message, so we all know who saw the message.
And we use the Slack threads for each message to discuss potential follow-ups.