1. Use Anna’s Archive (linked above). It uses their database in their search, as well as Libgen and others.
2. There’s also a Telegram bot for Scihub and Libgen which are handy: www.reddit.com/r/scihub/s/5p7FCk1IOH github.com/1337w0rm/Libgen-Telegram-Bot
3. Their Tor links are on wiki: en.wikipedia.org/wiki/Sci-Hub?wprov=sfla1 (check out the see also sections too).
4. For direct links: www.reddit.com/r/scihub/s/k6hFIhh51w
5. Use this free VPN if you don’t have one. You will not be able to connect without it on many connections: protonvpn.com

If you cannot find what you need, post on Wosonhj (above) or post on Twitter or Masto with the tag #icanhazpdf, search Research Gate, email the author, and try: unpaywall.org. Many unis require an open access preprint be hosted somewhere these days.