Have you just entered Korea?
Then you will need a SIM card.
There is a SIM card that can be opened with a passport.
Unlimited phone data messaging plan costs 36,300 won per month.
38,300won per month 4G data 10.3G
8, Beodeul-ro, Dongnam-gu, Cheonan-si, Chungcheongnam-do, Republic of Korea
https://maps.app.goo.gl/vJ3NWptFUVcaphVt6
충청남도 천안시 동남구 버들로 8
충청남도 천안시 동남구 버들로 8
www.google.com