You can't apply for 'Qualifying Test' without passing of "The Environmental protection and safety course".
check the file ' 1_safety course time table '
If you have not yet  taken "The Environmental protection and safety course", please check following information.
how to register the course by online :  check the file attached.
http://ieps.snu.ac.kr/
(but all of that is in Korean. you may want to ask some help to one of your labmates.