As per @Archisman Panigrahi advice, I'm posting a new question regarding qt5ct
. I've recently reinstall 22.04 and found that the Style drop-down menu only has Fusion and Windows, hence, I am unable to have Okular toolbar change according to Gnome's theme as I did before the re-installation. Weird thing is GTK is available in Standard Dialog drop-down menu.
The original solution is available here and my original question.
Kindly advise
qt5-style-plugins
– Lorenz Keel Jun 15 '22 at 07:30