If you wish your workflow to be kicked off by a particular action in Slack then use the Slack Trigger.
The Slack trigger allows you to receive notifications and trigger workflows when given events occur associated with the selected trigger operation.
Trigger Operations Available:Copy
On action (button or menu click)
On Slack event
On slash command
Select the Slack trigger. This can be done either at the create new workflow stage or updated within the workflow builder itself.
Use the instructions above to authenticate your trigger and select which event you want your trigger to listen to in order to kick off the workflow.
Slack Sub TypesCopy
Please note that the Also send to channel option in your Slack messages may not display as expected.
Replies in Slack will cause a workflow execution (via the Slack trigger) but replying AND posting ie. using the Also send to channel feature won't. This is to do with how Slack handles related
sub_types in their API.