RFC 9112 Requirement
Section: 9.8-10
Keyword: MAY
Servers MAY attempt to initiate an exchange of closure alerts with the client before closing the connection. Servers MAY close the connection after sending the closure alert, thus generating an incomplete close on the client side.¶
Reference: https://www.rfc-editor.org/rfc/rfc9112.html#section-9.8-10