Global Helpers

Hi all

Am building a portal customization for a customer.

In order to so I need to do an api call using the userId of the looged in user.

Have only found this; https://developer.zendesk.com/api-reference/help_center/help-center-templates/helpers/#user_name-helper

However that is not relevant as I must have a uniqe identifier, either a ID or an email?

Is that possible?