Здесь описана данная процедура:
https://admissions.sze.hu/hungarian-imm ... ertificate
https://surgoscovidteszt.hu/en/immunity-certificate/
Non-Hungarian citizens who have been in Hungary for LESS than 90 days can apply for a temporary certificate of immunity valid for 4 months at a government office in Hungary, following an antibody level test in a laboratory.