What do 당신 do if there's a request 당신 don't want to take?

당신 could politely tell them to ask for something 당신 DO want to draw. Either they understand, 또는 they aren't very mature. 당신 have the right to tell someone 당신 don't 또는 do want to draw a request. After all, it's a request, not an order.

just say I cant im kinda busy right now 또는 I gtg XD