First of all, my directory looks like this (simplified):

website/
  index.html
  files/
    script.js
  api/
    site.html

index.html is using script.js.
In script.js I want to fetch site.html

script.js:

fetch('./api/site.html')
.then(response => {
    response.json()
    .then(
        // code
    );
})

And instead of fetching example.com/website/api/site.html it fetches example.com/api/site.html

What should I change in fetch without specifying name of parent directory?