Yes. You can use a selfie for your K-ETA application as long as the photo clearly shows your face and meets the required facial photo standards.
A photo taken with a smartphone can be used, but the applicant’s face must be clearly identifiable.
Avoid using a blurry photo, a photo in which your face is obscured, or a heavily filtered or edited photo that does not clearly reflect your actual appearance.
For a smooth assessment, use a clear photo that accurately shows your current appearance when applying for K-ETA.