channel_reaction_remove

Delete a reaction the current user has made for the message. Returns a 204 empty response on success. Fires a Message Reaction Remove Gateway event. 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	user_id	Snowflake or @me	True