You need to create a child theme, add your font files to that child theme folder then with the child theme css add the appropriate css. Something like:
/*
Theme Name: Virtue – Child
Theme URI: https://themes.kadencethemes.com/virtue/
Description: Child theme for Virtue
Author: Kadence Themes
Author URI: https://www.kadencethemes.com/
Template: virtue
Version: 1.0.0
*/
@font-face {
font-family: 'engraversgothic_btregular';
src: url('tt0586m_-webfont.eot');
src: url('tt0586m_-webfont.eot?#iefix') format('embedded-opentype'),
url('tt0586m_-webfont.woff') format('woff'),
url('tt0586m_-webfont.ttf') format('truetype'),
url('tt0586m_-webfont.svg#engraversgothic_btregular') format('svg');
font-weight: normal;
font-style: normal;
}
h1, h2, #nav-second ul.sf-menu a, .kad-nav-inner .kad-mnav, .kad-mobile-nav .kad-nav-inner li a, .nav-trigger-case {
font-family: 'engraversgothic_btregular' !important;
}
Kadence Themes