Apple has nothing to do with VPN, VPN service is 3rd party.
See Hide My Mail (you need to have iCloud+ subscription.) , see the following Apple articles:
What is Hide My Email?
What is Hide My Email? - Apple Support
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Learn more about Hide My Email and iCloud+
Learn more about Hide My Email and iCloud+ - Apple Support
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Hide your personal email address in Safari on iPhone
Use Hide My Email in Safari on iPhone – Apple Support (UK)
Create and manage Hide My Email addresses in Settings on iPhone
Create and manage Hide My Email addresses in Settings on iPhone – Apple Support (UK)
Manage the apps that you use with Sign in with Apple
Manage the apps you use with Sign in with Apple – Apple Support (UK)
See also this Apple article: About iCloud Private Relay (part of an iCloud+ subscription)
About iCloud Private Relay - Apple Support
See also Lawrence Finch response in this thread.
How will this work with private VPN’s? - Apple Community