You probably just paste DOI codes there like most of us. Originally, sci-hub supported searching for codewords/topics (by using Google Scholar), but then their

You probably just paste DOI codes there like most of us. Originally, sci-hub supported searching for codewords/topics (by using Google Scholar), but then their IPs got banned from Google Scholar and the workaround is to install this extension. It modifies Google Scholar pages so that all links to paywalled articles are replaced with links to sci-hub pdfs of same articles. Google would never approve this extension, so you need to install it in dev-mode. But again, for most people's usage, it's completely unnecessary. Paste DOI -> get pdf works without any 'extensions' necessary.