Try as I may I don’t seem to find the dutch and german wrting aid for LO 6.2.3. I installed it on a Centos 7 linux from the download and I got English, French and Spanish writing aids which appears to be consistent with:
$ yum list *dict* *spell*
…
libreoffice6.2-dict-en.x86_64 6.2.3.2-2 installed
libreoffice6.2-dict-es.x86_64 6.2.3.2-2 installed
libreoffice6.2-dict-fr.x86_64 6.2.3.2-2 installed
…
But I cannot find e.g. libreoffice6.2-dict-nl.x86_64 for download (assuming it’s the one I need).