You’ll find these pages under the Platform section of Looker’s Admin menu. Choose one for more information:

• Actions
  Configure the ability to deliver data to services integrated with Looker.
• API
  Change API settings in Looker’s Admin panel.
• Embed
  Change settings related to embedding in Looker’s Admin panel.
• Extension framework
  Enable or disable Looker’s extension framework in Looker’s Admin panel.
• Marketplace
  Change settings related to Looker’s Marketplace in Looker’s Admin panel.
• Themes
  Customize the appearance of your embedded content from Looker.
• SMTP
  Configure Looker email settings, including custom email settings.
• Visualizations
  View, add, edit, and delete custom visualization types.