enqueue.php

/**
 * Enqueue Fontawesome icon font into your website.
 * Before adding this code, please ensure that you put Fontawesome CSS and webfont into fontawesome folder in your theme.
 */
function jet_enqueue_icon_font() {
	wp_enqueue_style( 'fontawesome5', get_theme_file_uri( 'fontawesome/css/fontawesome.min' ) );
}

add_action( 'wp_enqueue_scripts', 'jet_enqueue_icon_font' );