Applications for Schengen visas must be made at the embassy or consulate of the country the applicant intends to visit or, if they intend to visit more than one country in the Schengen area, the embassy or consulate of the country where they will spend the longest time.
If you intend to visit several countries in the Schengen area for equal lengths of time, you should apply at the embassy or consulate of the country through which you will first enter the Schengen area.
If Portugal is the only, the main, or the first country you will visit in the Schengen area, as explained above, you must apply for your visa at the Portuguese embassy or consulate in or responsible for the country in which you are legally resident. A full list of Portuguese embassies and consulates can be found at : https://embassies.info/portugal