Here is a link to the actual regulations for Covid-19 of the Ministry of Health (DGS) in Portugal.
Please note that you have to show your negative PCR-TEST (not older than 96 hours) at the MAIN ENTRANCE.
Only the Driver + 2 persons (Mechanic, Entrant or Representative of the Entrant or other) as long as one of the person's needs to be the Entrant or the representative of the Entrant can enter the Paddock.