Resource CUSTOMER_USER_ACCESS is blocked , how to fix?

[adwords clientcenter]

I need to get access to the email addresses of users who have access to the account.

Here's what I am using:

var gaqlQuery = "SELECT customer_user_access.email_address, customer_user_access.access_creation_date_time, customer_user_access.access_role FROM customer_user_access";

var reportRows = AdsApp.search(gaqlQuery);

this results in error:

"Exception: Call to GoogleAdsService.Search failed: Resource CUSTOMER_USER_ACCESS is blocked." 

How to fix?

thanks

[Google Ads Scripts Forum]

Reposting the last inquiry (https://groups.google.com/g/adwords-scripts/c/Sx42yNjl1kI) from the forum as it wasn't routed to our support queue. 

Cheers,
James

Google Ads Scripts Team