Sci-hub is great, but it should be your last resort. University librarians have explained this to me, but it has to do with how Sci-hub counts towards access counts of obscure journals.

Unpaywall provides an excellent browser extension. https://unpaywall.org/

If you have time, you can request a copy of a paper directly from the corresponding author. We love for people to be interested in our work, and we would rather you put that $40 access fee towards something that benefits society.