According to the local media, travellers need to show their certificate upon arrival. Passengers must have received their final vaccine dose a minimum of 14 days earlier. Kids less than 18 years of age will be allowed to enter with their parents without any certificate.
Apparently, the internal borders were supposed to open way back but it was postponed by two weeks because of the rising numbers of the positive cases. Thus, passengers coming from high-risk countries, meaning nations with a two-week incidence of more than 10 cases per 100,000 inhabitants, will need to get tested if they fail to show a vaccine certificate.
Those without any certificate, will have to take two tests, one immediately upon arrival in the country and the second test will be conducted three to five days after arrival.