11. Click on the dropdown "Select a role", then enter "service account user" in the search field. Scroll a little bit down until you find "Service Account User". Once selected, click on the button "Continue".
12. On the next step, leave the fields empty and click on "Done"
13. The new created service account will now appear. Click on the right side on the three vertical dots, then click on "Manage keys".
14. Click on "Add key > Create new key"
15. Make sure "JSON" is selected. Confirm by clicking on "Create".
16. A JSON-File should have been downloaded automatically to your computer. Make sure to keep this file to upload it later on Zappter.