visa sponsorship Korea Kowork work in South Korea 2025 non-teaching jobs Korea work visa korea rules XpatJobs korea employment visa fired in Korea visa jobs in Korea for foreigners job termination Korea foreigner expat career Korea resigning job korea freelance jobs Korea work visa status part-time jobs Korea work visa korea English jobs Korea employer no response Korea foreigner jobs Seoul foreign worker resignation KOTRA job fair LinkedIn Korea Seoul Global Center notice period korea employer shutdown foreign worker Korea Korea job search guide JobKorea change job korea visa foreign worker job change Korea job platforms quitting job Korea foreigner teaching jobs Korea foreign worker ghosted Korea company closed Korea visa Saramin unpaid salary Korea foreigner