I am working on a TYPO3 v10 LTS website with integration of the news extension v8.3.0. Many news are assigned to multiple categories and they are displayed on different detail pages according to their assigned categories. Now I would like to define one categories as master and use this category for the generation of canonical links to avoid duplicate content problems. On an older version of the website (TYPO3 v7 LTS) I used the solution explained here: https://www.typo3.net/forum/thematik/zeige/thema/116056/
I'm not so experienced with TYPO3 v9/v10 LTS yet, but I think that there must be a solution with routeEnhancers.
Any hints are welcome.