EU citizen retiring to Portugal - national health care eligibility

Good day,

My first post regarding the topic - please forgive me if I have overlooked the relevant answers posted throughout the forum.

I am a non-Portuguese EU citizen. I have lived, worked, and paid taxes in Canada throughout my working life (I have never worked in the EU, the family relocated to Canada decades ago). I am currently not covered by the national health care system provided by my EU country of birth.

Upon moving to Portugal, I would not work any more - I would cover my cost of living by savings/investments/state-funded pension from Canada. These funds will have been taxed in Canada, per the non-resident rules (I plan to give up my residency in Canada upon relocating to Portugal).

Where can I find more information about my eligibility for the Portuguese national health care system and the associated fees? I remember being told that there is no annual premium or tax, and - instead - every doctor/hospital/emergency room visit and every medical procedure is subject to fees (that do not appear to be very high), but this may have changed since I researched this years ago.

I would be very grateful if the forum participants could direct me to the appropriate Portuguese government websites or to an immigration guru. Or - maybe there are forum participants here who are in the situation I would be in upon retiring.

Thank you in advance!