Format for adding to a multi-select field via Zapier/API

Format for adding to a multi-select field via Zapier/API

I am using Zapier to act as an intermediary between a chatbot and Zoho Creator - to allow our clients to add records to the database via a communication. I have it working well, however when trying to pass a value to a multi-select field (it will only ever be a single vaqlue from the chatbot) I get the error :

code
: 3001
error : 1
Invalid column value for usage_type

I have triple checked that the value passed is in the list in teh exact same formatting.

What is the format to send a single string value to a multi-select field.