How to get custom object value properly displayed in my.token
i have a custom object with a field that i want to send to our internal system from marketo via Webhook
i have created my.token based on this custom object
{{my.domain}} = ${co_space_domainList.get(0).domainName} (srcipt)
and i have added this {{my.domain}} token to the webhook

the problem is that marketo seems to be unable to resolve the script and send the value of the token, instead i'm simply getting the the part of the token as-is:
...
/services/marketo/space/%7B%22codeBlock%22%3A%22%24%7Bco_space_domainList.get%280%29.domainName%7D%22%2C%22scriptingObjects%22%3A%7B%22custom%22%3A%7B%221026%22%3A%7B%22label%22%3A%22Space+Domain+Info%22%2C%22fields%22%3A%7B%223616%22%3A%7B%22label%22%3A%22Domain+Name%22%7D%7D%7D%7D%7D%7D
is there a work around this issues? are there any other ways to get custom object value as token/ any other field that can be sent in a webhook?