Hello! I have installed the paid version of the MailOptin plugin for Wordpress (https://mailoptin.io/) where it is ensured that it integrates with both ZOHO CRM and ZOHO Campaings. Running the integration for both CRM and Campaings gives me this error and the integration fails:

You don't have permission to access this resource.

Additionally, a 403 Forbidden error was encountered while trying to use an Error Document to handle the request

What is wrong?

Cheers