To create API keys on Exmo exchange please go to Exmo website: https://exmo.com
Log in into your account. If you do not have an account yet, create it by clicking on "Sign up" button on the upper right corner of the menu.
Log in to your account settings.
Go to the key API Keys configuration in the left pane. The exchange will automatically provide you with API keys.
In order for Investy services to work correctly with your account, go to the settings "IP Authorization and access" and make sure that you have disabled "API access from trusted IP addresses only".