Change spelling LibreOffice

Hi all!!

I was trying to change the settings for LibreOffice.
I wanted that it would notice the wrong spelling.

This works, but only in English.
I wanted to do this in Dutch (Belgium)

I can change all the languages, but doesn’t work for the spelling.

See screenshot. (doesn’t let me take screenshot with dropdown menu, but there are only english languages to choose from)

Any ideas?