あらすじ

下記urlのサイト所有者を追加がUIのどこを見てもなくユーザーと権限でメールを追加して"できた！"と思ってもPermission denied. Failed to verify the URL ownershipで死ぬ

解決法

https://support.google.com/webmasters/thread/4763732?hl=en&msgid=6359270
@Max i figured it out. Sort of. It is broken you are correct. You need to remove the properties from the new search console. Then go to the old webmaster tools, add it in there with your service address (the indexing API now works) and then you go back to the new search console and you can add it back in there. Google is constantly doing this so get used to it!

原因

おそらく古いからの移行フェーズでリニューアルされた方に機能が持ってこれてないのかもしれないです。