In my Service project, I am trying to copy the value in the Organizations field to a custom field. I read an earlier post that had the same request and I tried doing what they did but the automation rule keeps failing.
Below is the rule and the JSON for updating the "Customer" field to equal the value of the Organizations field. The rule fails with a message saying "Specify the value for Customer in an array (Customer))"

I have also tried a "add" in place of "set". The Customer custom field is a multi-select dropdown. I originally thought this issue might be that the Organizations value I was trying to set did not exist as a value in the Customer field. I add the value I was setting to the Customer field but that did not resolve the issue.
Any help is appreciated.