replying bc it's pertinent and one of the first results for google (and i wish it were here), but for distros that support it, there's a PPA for a qt6 configuration tool just like the qt5 one that things like Linux Mint ships with. it's experimental but it did the trick just fine. https://launchpad.net/~savoury1/+archive/ubuntu/qt-6-2

hope this helps any fellow people coming from google and you two (even though i doubt either of y'all will see this lol)