Workflow Trigger for Survey Completion

I’d like to be able to create a trigger for a workflow to execute once a survey is completed. In this example I have a survey built to go out to customer’s after they have finished their onboarding period. 

I would like to be able to notify my slack channel once this has occurred so that I know the moment a survey has been completed.

Right now it seems like most triggers are conversation based but this would be a good example of a user completing an action and then being able to take action directly afterwards.