For openSUSE Leap 15.6 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:wolfi323:branches:KDE:Frameworks5/openSUSE_Leap_15.6/home:wolfi323:branches:KDE:Frameworks5.repo
zypper refresh
zypper install qmlkonsole
For openSUSE Leap 15.5 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:wolfi323:branches:KDE:Frameworks5/openSUSE_Leap_15.5/home:wolfi323:branches:KDE:Frameworks5.repo
zypper refresh
zypper install qmlkonsole