Is there a way for foreigners to find a studio apartment in Gangnam?

Hello! It's been about 6 months since I came to Korea, and I'm currently looking for a one-room apartment in Gangnam. It's really tough because when I go to real estate agencies, they immediately reject me just because I'm a foreigner. I'm worried about the high deposit, so I'm wondering if foreigners can also get a lump-sum deposit loan. Does anyone have a similar experience? I've tried using the Zigbang app and visited about 5 real estate agencies, but they all say it's difficult just by showing my alien registration card... Can anyone recommend a good real estate agency or app? I would really appreciate it if you could share your experiences!