ManaKeep provides 12 font styles for you to choose from in the editor, but if you want to use your own custom font you can do that as well =)
If you go to Google Fonts, and check Use Font, they provide a CSS option; you can add this to the CSS tab in the ManaKeep Editor, then specify what you want to use the font for. So for example you could do something like:
/* import the Montserrat font from google */
@import url('https://fonts.googleapis.com/css2?family=Montserrat&display=swap');
/* Use the Montserrat font for all your header elements on the site */
h1, h2, h3, h4, h5, h6 { font-family: Montserrat; }
/* Use the Montserrat font for other elements on your site */
body, label, input, textarea, select, button { font-family: Montserrat, sans-serif; }To use the MontSerrat font from Google everywhere on your site, or any other font listed there =)