Please try to do the following in order to add breadcrumbs to your website. Install and activate Breadcrumb NavXT plugin, go to your
public_html/wp-content/themes/sydney folder via SFTP or cPanel, open
header.php file with a text editor, add the following code at the bottom and save changes.
<div class="breadcrumbs" typeof="BreadcrumbList" vocab="https://schema.org/">
Please note that you have to override modified
header.php file in a child theme (just copy it to the child theme folder) in order to avoid losing your modification after theme update.
Please let me know if you need more help.
Kind Regards, Roman.