In the files you can upload a font in ".tff" format. For clarity you can create a folder called "Fonts". It is sufficient for this folder to have restricted access only for admins.
For every font you can choose for which formatting (i.e., italics, bold etc) it should be used for via the 3-point-menu on the right. Every formatting option should only be used for one font.
Attention
Please refrain from using special characters like '(' or ')' in the name of folders and files.