Obtaining a health certificate was required for applicants to enter Iran

The Ministry of Health announced; 

All travelers applying to enter the country from air, sea and land destinations are required to present a health certificate, certified by the competent health authorities of the country of origin in English.

If you do not have a health certificate at the destination airport, if you are a foreign passenger, you will not be allowed to enter the country. 

If the passenger is Iranian, he will be guided to quarantine determined by the Ministry of Health for 14 days at his own expense.