If you're not receiving emails from this Moodle server it may be due to your organization spam filter intercepting our messages. Please have your technology team whitelist the domains @ethinkeducation.com and @ethinksites.com.
To get an enrollment key, click the tile of the course to which you want access. On the left side of the resulting page you will see a list of Moderators/Teachers/etc. Click a name and on the resulting page you should see their email address under "User Details". Click the email address and send them a message. If you don't see an email address, go back and click another name.