To generate an API key go to the upper right corner in CloudHealth and click on your name.  Then click again on your name in popup menu.

Under settings you will see the key displayed.  At the side there is a small clipboard icon to copy the key to your clipboard.  You can also generate a new key. 

Notes:

- Standard users do not have API access and cant get a API key, only "Power" and "Admin" users have or can create an API key.

- Users who only have access to a sub-org level, will only have have API access to the data of that Sub-org and any child orgs below.