Basically, "ㅋㅋㅋ" is like lol. It's internet slang. I don't know if the writer wrote intentionally or not but "완천" is supposed to be "완저" which means "totally" and "귀욥게요" is supposed to be "귀엽게요"
If the writer is Korean I believe he/she did it intentionally. So it means It's totally cute.