There is no option to edit Webex Meetings email templates in site administration or control hub.
The ability to customize email templates is missing in Cisco Webex Control Hub.
Why is the edit email template option missing in Control Hub?
The edit email template option is missing on the Site Administration page.
For security reasons, email templates are disabled on all new Webex sites. If you need help with enabling email templates, contact Webex Support. For help, see: WBX162 - How Do I Contact Webex Customer Services or Technical Support?.
Note: Webex accounts with 100 or more host licenses can request email templates enabled on their site. As a workaround for under 100 host licenses, use the Cisco Webex Meetings Scheduler to customize email templates: Schedule and Join Meetings with Cisco Webex Meetings Scheduler for Microsoft Office 365.