In an automation, when creating an issue, I want to check if the email received in a customfield already exists as a customer.
I think it should be something like that, but it always tells me that it doesn't exist.
"{{issue.mycustomfield}}" in (accountId("{{issue.mycustomfield}"))

What is the correct way to check if an email exists as a customer?
And to add to the query if it is a customer in a specific project?
Thanks!!