I gave KDE access to my Google account, I was asked for a confirmation code by phone 3 times and then I had to confirm the confirmation codes by phone again, everything went well - access was granted to KDE and they can do whatever they want with my account.
Sorry to inform you google has restricted KIO support for no apparent reason and mandates the KDE community to do go through stupid bureaucratic steps to hope to fix this:
I studied the provided access to see WHAT EXACTLY Google allows to use: there is Youtube and Calendar, but no Drive, despite the fact that when providing access it was indicated - Mark all.
Most likely, KDE is misleading users by indicating that KDE Online Accounts provides access to Drive, such access is NOT, but there is access to use and change my Google account data
Itβs very strange that Google doesnβt provide access by application passwords, thatβs exactly what I thought, that it doesnβt work because of this, but entering the application password didnβt help
The issue has been resolved: the network account has been removed from the settings