cannot access iCloud account using Safari browser

I phoned Apple and a senior supervisor walked me through all the steps short of erasing and re-installing. What I believe is the problem for me is that I have an older MacBook pro that has Safari 13.1.2 and cannot be updated to the latest Safari update which is 14.1.

Consequently, I am unable to access iCloud with Safari. I downloaded and installed Firefox browser and everything works fine. Just have to remember to unclick any firewalls so that Firefox can install.

Same thing for my iPad which is an older iPad and Safari cannot be updated just like on my older MacBook Pro.