WordPress ajax call with Fetch API

script.js

// php file
function enqueue_scripts() {
    wp_enqueue_script( 'public-js', plugin_dir_url( __FILE__ ) . 'js/script.js', array(), '1.0', true );
    wp_localize_script( 'public-js', 'localizeObj',
        [
            'ajax_url' 	=> admin_url( 'admin-ajax.php' ),
            'nonce' 	=> wp_create_nonce( 'prefix_public_nonce' ),
        ]
    );
}

function load_more_posts() {
    $security = check_ajax_referer( 'prefix_public_nonce', 'security' );
    if ( false == $security ) {
        return;
    }
    
    // post query, loop...
}
add_action('wp_ajax_load_more_posts', 'load_more_posts' );
add_action('wp_ajax_nopriv_load_more_posts', 'load_more_posts' );


// script.js file
const target_div = document.querySelector('.posts');

const bodyParams = {
    action: 'action=load_more_posts',
    nonce: '&security=' + localizeObj.nonce,
}

fetch(localizeObj.ajax_url, {
    method:"post",
    headers: { 'Content-Type': 'application/x-www-form-urlencoded' },
    body: bodyParams.action + bodyParams.nonce   
})
.then(function(res) {
    return res.text();
})
.then(function(data) {
    //     console.log(data);
    const parser = new DOMParser();
    const items = parser.parseFromString(data, 'text/html');
    const postItems = items.querySelectorAll('.items');
    
    postItems.forEach(function(postItem) {
        target_div.append(postItem);
    });
})
.catch(function (error) {
  console.log(error.message);
});