Canonical points to a different URL
What this means
The canonical URL differs from the page's own URL once trailing slashes are normalised, which tells search engines to index the other URL instead of this one.
How to fix it
Confirm the target is the version you want indexed; if this page should be indexed on its own, point the canonical at itself.
Fix effort
This check needs review: the change can be drafted for you, but a person has to approve the wording or choose the target before it ships.
Authoritative source
https://developers.google.com/search/docs/crawling-indexing/consolidate-duplicate-urls
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