xca from home:computersalat:lap project

For 15.6 run the following as root:

zypper addrepo https://download.opensuse.org/repositories/home:computersalat:lap/15.6/home:computersalat:lap.repo
zypper refresh
zypper install xca

For 15.5 run the following as root:

zypper addrepo https://download.opensuse.org/repositories/home:computersalat:lap/15.5/home:computersalat:lap.repo
zypper refresh
zypper install xca