For openSUSE Tumbleweed run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:badshah400:Staging/openSUSE_Tumbleweed/home:badshah400:Staging.repo
zypper refresh
zypper install xournalpp
For openSUSE Factory ARM run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:badshah400:Staging/openSUSE_Factory_ARM/home:badshah400:Staging.repo
zypper refresh
zypper install xournalpp
For 15.6 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:badshah400:Staging/15.6/home:badshah400:Staging.repo
zypper refresh
zypper install xournalpp
For 15.5 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:badshah400:Staging/15.5/home:badshah400:Staging.repo
zypper refresh
zypper install xournalpp