Can foreigners also find a studio apartment in Gangnam?

I want to find a one-room apartment in Gangnam as a foreigner, but I have a few questions. Is there a way for foreigners to live in popular areas like Gangnam or Hongdae? I have been living in Korea for about 6 months now, and I want to find a one-room apartment in the Gangnam or Hongdae area because of my job. However, I have been rejected at some real estate agencies because I am a foreigner. What should I be careful of when signing a monthly rent or lump-sum lease agreement as a foreigner in Korea? I am also curious if the conditions for the deposit and monthly rent are different. If there are any real estate agencies or recommended apps that are friendly to foreigners in Gangnam or Hongdae, please advise. Also, sharing your experiences in this process would be very helpful.