libQt5Gui5 from home:fusionfuture:branches:KDE:Qt:5.15 project
Select Your Operating System
Add repository and install manually
For TW run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:fusionfuture:branches:KDE:Qt:5.15/TW/home:fusionfuture:branches:KDE:Qt:5.15.repo zypper refresh zypper install libQt5Gui5