Why does Webhook Triggered workflow not appear for me in Slack Workflow builder?

Slack has implemented permissions around the Slack Workflow Builder triggering mechanisms such as Webhook triggered workflow. If you begin a new Workflow Builder in Slack and cannot see Webhook Triggered as a starting point, follow these steps:

• You'll need to be a Slack Workspace Admin or Owner, or the ability to modify Slack's Workspace Settings
• Go to Settings and Administration in Slack, then click Workspace Settings
• Go to the Permissions tab:
  
• Scroll down to Start Workflows with Webhooks, then check "Workflow Builder users can use webhooks":