After signup click the "Set up on the Free plan" button at the top of the page
After setting up your plan you should be on the following page. Click HTTP API.
Now copy your API key, which you can see highlighted in the screenshot below. You don't need to follow the instructions because Divjoy has everything setup for you already.
You can also find your API key by navigating to your project settings via the settings link at the bottom left of your analytics dashboard.
- Add your API key to your codebase