Inside the Mailgun Control Panel (options displayed down the left-hand side on a dark column), the API keys appear on only one page. To view the API keys, use the following instructions:

1. Click on Settings on the left-hand side of your the Mailgun dashboard.
2. Select Security & Users from the menu below on the left-hand side.
3. Click on the API security tab.
4. On the following page, under the API Keys section, you'll see both your Private and Public API keys.
5. Click on the eye icon to make the full API key visible.