To install a hyphenation dictionary:
- In Finder, hold and select Go>Library.
- Open the Spelling subfolder.
- Create a subfolder and name it after the hyphenation dictionary's locale ID, i.e. where the dictionary's filename is in the format hyph_xx_XX.dic, the subfolder should be named xx_XX.
- Place the hyphenation dictionary in the subfolder.
- Quit and reopen Affinity Publisher.
- In Affinity Publisher, select Edit > Preferences.
- In the Preferences window, select Tools.
- To the right of Additional dictionary folder, select Open.
- Create a subfolder and name it after the hyphenation dictionary's locale ID, i.e. where the dictionary's filename is in the format hyph_xx_XX.dic, the subfolder should be named xx_XX.
- Place the hyphenation dictionary in the subfolder.
- Quit and reopen Affinity Publisher.
The newly installed dictionary is available in the Hyphenation pop-up menu in the Character panel's Language section.