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