Shopify Flow To Klaviyo Creating Tags

Hi - I am using Shopify Flows in conjunction with Collabs, when a creator is approved in Collabs, I want to push an event to Klaviyo and have it tag them so that I can then create a segment in Klaviyo based on this. I want them all tagged with the same wording "Approved Creator" - anyone know how to do this? I went to the Customer Properties and did this: {"tags": "{{Approved_Creator}}"} but am getting "Approved_Creator" is invalid. Replace this variable. - any way to do it without a variable?