zstd from home:dliw:branches:Emulators project
Select Your Operating System
Add repository and install manually
For 15.5 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:dliw:branches:Emulators/15.5/home:dliw:branches:Emulators.repo zypper refresh zypper install zstd