The easiest way to change your images' caption and title font is to choose your preferred option from a list available directly from Modula's settings.
However, if you want to use a specific one that is unavailable in our list, you would need to use a plugin to load it on the site and then add custom CSS to apply it to the caption and title.
For example, a plugin you can use would be Custom Fonts.
Once you upload the font files, you can apply the font using CSS in Appearance > Customize > Additional CSS.
An example of such code would be:
.modula .modula-items .figc .jtg-title, .modula .modula-items .figc .description { font-family: fontname !important; }Replace the value 'fontname' with the name of the font you added.