emoji / emojis
Plural form; use in running text.
Emoji is usually singular. The plural is emojis. An emoji suits casual writing and email, not standard prose such as reports, news, or formal letters. In a quotation, leave any emoji where it stands.
Examples
UseShe sent three emojis.
AvoidShe sent three emoji.
UseThanks for the key 🔑. (casual note or email)
AvoidThe report said the gate was closed 🙂. (formal writing)