Backup db
=> run wp cli:
wp db export
Document: https://developer.wordpress.org/cli/commands/db/export/
Backup code on terminal:
zip -r backup.zip wp-admin wp-content wp-includes index.php wp-comments-post.php wp-cron.php wp-login.php wp-trackback.php wp-activate.php wp-mail.php xmlrpc.php wp-config-sample.php wp-config.php wp-links-opml.php wp-settings.php wp-blog-header.php wp-load.php wp-signup.php .htaccess
Or quickly:
zip -r backup.zip wp-admin wp-content wp-includes wp-*.php .htaccess xmlrpc.php index.php .htaccess