Creating new words in the es_ES dictionary of OnlyOffice in a Docker installation

I have an OnlyOffice installation on my Alma Linux server using Docker. However, the Spanish dictionary (es_ES) has a very limited number of words. I’ve tried adding new words to the existing dictionary, but I can’t find a way to do it.

Is there any way to add new words to that dictionary?

Or is there a way to upload a new dictionary for the es_ES.dic language that will work with the spell checker?