To generate API keys, login and go to your account settings. Here on the left if you have API enabled you will see an option for "API Keys" (see image below).
Here you are able to generate an API Key by entering the description of the Key and clicking on "Generate". This will display an API Key that you will be able to use for integrations. If you need the API documentation you can view it on this page as well in the top right corner or at