Issue including typography

I followed the instriuctions in the README

yarn add @tailwindcss/typography

added the plugin to your tailwind.config.js as mentioned in the README.

Shouldn't the following command generate a final css that contains the typography classes?

npx tailwindcss build src/styles/index.scss -o output.css

Adding the following line to the source file after @tailwindcss base; is not mentioned in the document. @tailwindcss typography;

But even that makes no difference. This line is not replaced at all and is retained as is.

Can you tell me what I am doing wrong or what step I have missed?