I need your advice.

[Reece]

I assume since you had spilled coffee that you then cleaned off with water. Can't see it so may not be of much help but you could try:
placing keyboard in dry towel then placing in spin drier for a few minutes to get most of the moisture out, then leaving in the sun for most of a day, could try spraying with electronic circuit cleaner if you have any available. Hope this helps!