For this you need to have a consolidated blog or website with a considerable number of readers, and also offer content that is exclusive and that they are willing to pay.
It works in the first place offering free content, to later launch for sale content or tools that have special or deeper details.
For example, if you have an SEO-themed blog, you can pay a certain amount to subscribe to exclusive material, or if you have a cooking page, get more detailed tutorials about a certain recipe.
