If you want to connect an external application though the Veeqo API then you will need to generate API credentials in the form of an API key.
Login into your Veeqo account
Navigate to Employees page
Click on your user or + New Employee (easier to track application activity)
Click Create/Update API Key
Your API credentials will displayed on screen. Treat them like you would any other password, since whoever has access to the API Key has full API access to the Veeqo account.
This information can also be found in the API Documentation