How to delete an alias of apple id/email?

Hi guys,

Can you help me a little bit with some problem, more precisely, I want to delete an alias from my email/iCloud account and I do not have any option to do this as you can see from the screenshots attached, any idea how or what should I do to delete it?

The mail user is the one with @me.com and I want to delete/remove the one with @icloud.com and as you can see there is no option to delete this alias...

Thank you