Preliminary Remarks
Service accounts are used by applications such as Frisbii Media for authorized API calls. If an application authenticates itself as a service account, it has access to all resources (theme, subscription, etc.) to which the service account has access.
In the context of In-App Purchases, a service account is used for the authentication of Frisbii Media to the Google services.
Create service account
In the Google Play Console:
- Select the desired Google Cloud project 
- Click the "+ Create service account" button 
- Create service account: 
 - Select name for service account. This name is only visible internally and can also be changed
 - The service account ID is automatically assigned based on the selected name
 - The description for the service account is optional
 - Click on "Create and continue"
- Specify access and role for service account: 
 - Select the "Service account user" role in the Service accounts area- - Alternatively, the "Owner" role can also be selected 
 - Click on the "Next" button
- Link service account with users: 
 - This option is not mandatory for the use of Frisbii Media, but may be necessary depending on the organizational structure
- Complete creation: 
 - Click on the "Done" button to complete the creation of the service account
Create key for service account
A key must be created so that the created service account can be used as authentication by Frisbii Media. In the Google Play Console:
- Open created service account 
- Select "Key" tab 
- Click the "Add key" button 
- Select the "Create new key" option 
- Select key type "JSON 
- Click the "Create" button to finish creation 
- The key is now downloaded as a file 
The content of the key file is then stored in the Frisbii Media Merchant Backend.