For single character Emoji you can use the unicode name ("eyes", "fire", etc).
For multi-character Emoji you must use the discord format. Type \:emoji: into
a discord chat and paste that into the Text
For example :thumbsup::skin-tone-3: is "👍\127997".
A custom emoji will look like <name:id_number> or name:id_number.
See examples/ping-pong.hs
for a CreateReaction request in use.