Enable the enhanced email template editor page
Turn on the enhanced email template editing experience in the Customer Service Hub and Customer Service workspace apps. If you need to, you can turn off the enhanced email template page for a specific app. And then, the users of the app see the default email template editor page.
Enable the enhanced email template editor for Customer Service apps
In Power Apps, select the environment the environment that contains your solution.
Select Solutions, and then select the solution in which you want to turn on the enhanced template editing experience.
Note
Don't select the default solution to configure the template.
Select Add Existing > More > Setting.

On the Add existing Setting Definition pane, select the Enable the New Email Template Editor option and then select Next.
Select Add on the Selected Setting Definition to add the Enable the New Email Template Editor option to your solution.
Go to Add Existing > App > Model-driven app> Add existing model-driven apps pane. Select the Customer Service workspace and Customer Service Hub apps.
Select the Enable the New Email Template Editor option. The Edit Enable the New Email Template Editor pane appears.
Set the Setting environment value option to No on the Edit Enable the New Email Template Editor pane.

On the Edit Enable the New Email Template Editor, in the Setting app value section, the Customer Service Hub and workspace apps are displayed.
Select New app value for the app, and select Yes for the specified app.

Select Publish All Customizations.
See also
How to create an email template in model-driven apps
Customize an email template using the template editor
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