How to include a service user in IAM owner role?

Hi guys, I am just testing out Zitadel and want to implement a action(v2) to integrate with my webhook for syncing successfully registered users. For now, I have set targets and actions but the webhook is not triggered. As far as I know, if I want to test this from an API client, I need to have IAM owner role. How can I achieve IAM owner token for that or add a service user to IAM Owner role? I think I messed up somewhere in the config because I can't export token for my current IAM user. Please enlighten me.