Back End > Required E Mail for New Subscriber

I have set the email field as required, which works correctly for front end users.

However, when an admin tries to add a new subscriber in the back end (regardless of the plan) the email field is not showing as required. Is this a bug or have I missed a different setting somewhere?

For unclear reasons, maybe it was because customers required me to do that in the past, I made the field optional

If you want to have it required:

- Get this file, unzip it
- Upload the received file to administrator/templates/isis/html/com_osmembership/subscription folder

Then the field will be required as expected

Tuan