All of Osano's developer documentation can be found in full at developers.osano.com.
In the Osano Web Application (my.osano.com):
Log in as an Administrator.
Click on “Settings” (gear icon on the top-right of the screen).
Choose API Keys.
Click the green “+” to add a new key.
When prompted, click “confirm” to generate a new API Key.
Copy this key for safekeeping. (Once it disappears, you will not be able to access it again.) The API key will last for 5 years before it expires and is no longer valid.
In your preferred API Client (ex. Postman or similar tools):
In your API request:
Method: POST
Endpoint: <https://customer.api.osano.com/graphql>
Set the Authorization header to be Bearer [API KEY] where you replace [API KEY] with the value you created in step 1 above.