My JSON won't work for column formatting to color code the calendar on my MS Teams SharePoint Site

I would like to color code the calendar events based on choices for the “Source” category column, and I understand you can do this by going into List Settings<(Column name) <Column Formatting. I used chatGBT to create a JSON, but for some reason my events are still all black. I've included the JSON below. All the other column formatting questions that I have seen online look much different, so I've also attached a screenshot of the “Edit column” page for the column I would like to add conditional formatting to change the color of the event boxes.