function lcpUpdateImageSizes(imageSizes) {
    // Validate the input to ensure it's an array
    if (!Array.isArray(imageSizes)) {
        console.error('Invalid image sizes data');
        return;
    }

    // Prepare the form data to send to WordPress to update the theme settings
    const updateData = new FormData();
    updateData.append('action', 'update_lcp_theme_settings');  // WordPress action hook
    updateData.append('image_sizes', JSON.stringify(imageSizes)); // Send image sizes as a JSON string
    updateData.append('nonce', customImageSizeAjax.nonce); // Send the nonce

    console.log('Sending data to AJAX:', updateData);  // Log the data for debugging

    // Send the AJAX request
    fetch(customImageSizeAjax.ajax_url, {
        method: 'POST',
        body: updateData, // Send form data directly
    })
    .then(response => response.json())
    .then(data => {
        if (data.success) {
            console.log('Theme settings updated successfully.');
        } else {
            console.error('Failed to update theme settings:', data.message);
        }
    })
    .catch(error => {
        console.error('Error updating theme settings:', error);
    });
}