Verify sequential position integers and item URLs inside BreadcrumbList itemListElement arrays.
BreadcrumbList schema replaces messy URL slugs with clean clickable hierarchy trails in SERPs.
{
"@context": "https://schema.org",
"@type": "BreadcrumbList",
"itemListElement": [
{ "@type": "ListItem", "position": 1, "name": "Home", "item": "https://example.com/" }
]
}