Agregar Google Fonts a tu sitio WordPress

functions.php

<?php
/**
 * Enqueue styles
 */
function my_theme_enqueue(){
    wp_register_style( 'my-theme-google-fonts', 'https://fonts.googleapis.com/css2?family=Roboto&family=Ubuntu:wght@400;700&display=swap' );
    wp_enqueue_style( 'my-theme-google-fonts' );
}
add_action( 'wp_enqueue_scripts', 'my_theme_enqueue' );

/** 
 * Preload styles
 */
function my_theme_preload_styles( $html, $handle, $href, $media ){
    if ( 'my-theme-google-fonts' == $handle ) :
        $html = '<link rel="preconnect" href="https://fonts.googleapis.com">';
        $html .= '<link rel="preconnect" href="https://fonts.gstatic.com" crossorigin>';
        $html .= '<link href="'. $href .'" rel="stylesheet" media="'. $media .'">';
    endif;

    return $html;
}
add_filter( 'style_loader_tag',  'my_theme_preload_styles', 10, 4 );