Hear to Brand and Assets > Font Management
If you’d like to use Google Fonts, tick Google Fonts, pick from the dropdown then click Add
If you’d like to use your own Font, select Custom Fonts, name the font, upload all 4 font options, then click Add.
What if you don’t have all the font formats?
You can consider using online conversion tools such as https://cloudconvert.com/font-converter to convert missing file formats. Please check your font license first to ensure this is within your license terms.