Emoji must be a string or GuildEmoji/ReactionEmoji code example
Example: how to send emoji as ID discord.js
msg.channel.send("<:bat_food_full:786954379223367710>");
//msg.channel.send("<:emoji_name:ID>");
/*---
To get ID, in discord; type "\" then the name of your emoji
For Example, type
\:bat_food:
and it will return
<:bat_food:786554369626347415>
---*/