You will find the corresponding option inside

Navigate to Dashboard → ArticleMag → Typography

You will find the following options:

Body Typography: Allow to you change body typography font family, font weight, font size, line-height.
Menu Typography: Allow to you change Menu font family, font weight, font size.
Sub Menu Typography: Allow to you change Sub Menu typography font family, font weight, font size, line-height.
Heading Typography: Allow to you change Heading typography font-family, font-weight.

Add New Custom Font: Allow to you add new custom font using google font.