When someone asks “Who is it?”, state your name — do not merely say “Me.” Jābir knocked on the Prophet's door; he asked: “Who is it?” Jābir said: “Me.” The Prophet ﷺ said, disliking it: “Me, me?” (al-Bukhārī). Identify yourself clearly so the host knows who is there.
العربية: عن جابر رضي الله عنه قال: أتيتُ النبيّ ﷺ فدققتُ الباب، فقال: «من ذا؟» فقلت: أنا، فقال: «أنا أنا» كأنه كرهها. (البخاري).
When asked who is at the door or on the phone, say your name — not just “It's me.”