Log into your Dashboard with appropriate credentials.
Select the mode (Test or Live) for which you want to generate the API key.
You have to generate separate API Keys for the test and live modes. No real money is used in test mode.
Navigate to Settings → API Keys → Generate Key to generate key for the selected mode.
The Key Id and Key Secret appear in a pop-out window as shown below:
After generating the keys from the Dashboard, download and save them securely. If you do not remember your API Keys, you need to re-generate it from the Dashboard and replace it wherever required.