Generating the API key
Please follow the instructions on "Getting Started With The API" in BambooHR's documentation.
To generate an API key, users should log in and click their name in the upper right-hand corner of any page to get to the user context menu. If they have sufficient permissions, there will be an "API Keys" option in that menu to go to the page.
How to find my subdomain?
The subdomain is used to access your account (If you access BambooHR at https://mycompany.bamboohr.com, then the subdomain is "mycompany").