`og.url`

Default: warn
Plugin: og

A page has an og:url that matches its canonical URL.

Why: Apps use og:url to group shares of the same page. When it differs from the canonical URL, shares of one page are counted apart. Without a canonical link, the rule compares against the page URL, when it is known.

When off: pages without, or with a different, og:url pass.

<!-- ✗ Fails -->
<link rel="canonical" href="https://example.com/about/" />
<meta property="og:url" content="https://example.com/about-us/" />

<!-- ✓ Passes -->
<link rel="canonical" href="https://example.com/about/" />
<meta property="og:url" content="https://example.com/about/" />

References

The Open Graph protocol: og:url is the canonical URL of the page. The rule warns.
Google: How to specify a canonical URL: The canonical URL that og:url should match.