Debugging Custom Function with API Connection

Debugging Custom Function with API Connection

We are developing a extension to use third-part app thru OAuth 2.0.
We connected it with connector and authorized it in connector.

We are debuging custom function to use connector API in extension.
But can't get test response of the api in excuting of custom function. 
can you let me know the method to test connector api in custom function?

Zoho gives the execute option to test the custom function. It is available with common functions. but in this case, what use OAuth 2.0 connector, I can't get the test response from connector api. QB api response have several type and I can't code next line without test response.