Just tested this on Plasma 6.5 Beta 2, and it doesn’t work here either. I could create the account, but when I access gdrive:/ in Dolphin it says “Access denied to .” I selected access to Contact and calendar systems. So an upgrade of Plasma probably won’t fix it for you.
Didn’t even realize Plasma had this feature and I reckon support for it is bad because many here try to get away from Big Tech overall and moving to FOSS alternatives like Nextcloud etc.
One alternative to KIO probably would be to use contacts and such via Thunderbird (I used this for years).
Having said that, there might be something wrong with my KDE PIM installation, maybe that’s why. What do you want to achieve with this? Is it just about access to Gdrive?
I abandoned the whole KDE path when I discovered something called ExpanDrive. It just works - well, still having issues with one of my gmail accounts. But Gnome just failed, so, no time to cry
I’m seeing the same issue for an out-of-the-box install. I’m trying to access my Google Calendar (so am using Gnome Calendar because that’s what the UI suggested) and went to Online Accounts.
As per the OP, I get a dialog but nothing works (as described above).
Is this because Google changed some field names recently (maybe not so recently - when they move to two-factor authentiction)? Or something else? The signon-ui “embedded” browser doesn’t give me an option to view source or anything like that…
Alternately: Is there a way to do the auth via the CLI (and I am aware that OAuth2 requires user interaction) or some other method that triggers the default system browser?