Limiting time on specific website

Hi,

I wish to restrict the amount of time a specific website (vtm.be) is used per day, without fully blocking it.

The website is currently put under the "News" category whereas it's a video streaming platform. 

I would like either to put a time constraint on the website itself, or move the website to the right category.

But the app only allows to block or allow the website, not just to limit time on it like for platforms. 

Any trick I missed? Thanks/

Pim