Hi @Yonnic,
There are undocumented APIs that do exist at the moment. You can use them, however, please proceed with caution as these APIs might change in the future without a warning.
But, you can go in the UI and open the developer tools to see the network requests being made to https://analytics.services.netlify.com/v1/<site-id>/.... This might not be the most ideal way to use the API, but might work for the time being depending on the use case.