channel_reactions

Get a list of users that reacted with this emoji. Returns an array of user objects on success. The emoji must be URL Encoded or the request will fail with 10014: Unknown Emoji. To use custom emoji, you must encode it in the format name:id with the emoji name and emoji id

Count	Name	Type	Required
1	channel_id	Snowflake	True
2	message_id	Snowflake	True
3	emoji	Snowflake	True
4	after	Snowflake	False
5	limit	Integer	False