The account settings section in Kentico is where you'll need to specify the user credentials that will be used to connect to your GatherContent account via the API. You have to set all these parameters in order to start using the integration.
Go to Dashboard and select "Settings"
Select "Integration" and "GatherContent"
Enter your GatherContent User Email Address, API Key, Platform URL, specify the Media Library Name where you would like all media items to be imported and click "Save". You can get instructions on generating your API Key in our help docs.