how to change the font

In a previous thread for this same issue the person was told to redownload the fonts as this guy said

“i have checked amd our our version we do not have an option to re install the fonts under advance then tools. Can you please assist. We also removed the pluging and reinstalled it agian, but it stays the same”

Ive also done the above and there is no where to reload the fonts on my version which is the latest. Ive uninstalled and redownloaded. Ive also gone to my file directory and the fonts are showing on the server.

How can I fix this please as the invoices are practically unreadable

Thanks