I've checked docusurus.config.js
and I can not see that sitemap plugin is installed but sitemap.xml exists in build directory.
What defines parameters how is sitemap generated?
As per the documentation of the docusaurus:
If you use the preset @docusaurus/preset-classic, you don't need to install this plugin as a dependency.
You can configure it like this
module.exports = {
presets: [
[
'@docusaurus/preset-classic',
{
sitemap: {
changefreq: 'weekly',
priority: 0.5,
ignorePatterns: ['/tags/**'],
filename: 'sitemap.xml',
},
},
],
],
};
Check this reference for more info.