The company that manufactures UVA1 units is Daavlin. They list distributors in South Korea, so it may be possible for you to get one. They have a contact form for inquiries on their site. Just go to daavlin.com for more information.
And remember that of course, you want to make sure that you very carefully follow all of your doctor's instructions for treatment, and keep all of your follow-up appointment for skin cancer surveillance and to track your symptoms and recommended dosage. Your doctor will start by running a skin test, to determine what dose you need to start at.
Do not *ever* get in the headset that "more" will be "better". You need just the exact dose prescribed to be beneficial for your immune system and not cause you to burn to a crisp. The sessions are extremely short (a matter of mere seconds) so always check and double check your settings, you cannot be too careful in using it. Also, be sure to get protective equipment such as the UVA1 goggles and a face shield, and to read and follow all of the safety instructions.
Let us know what you find out, and how things go for you.