For openSUSE Tumbleweed run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:mnhauke:sdr-devel/openSUSE_Tumbleweed/home:mnhauke:sdr-devel.repo
zypper refresh
zypper install nlohmann_json
For openSUSE Factory ARM run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:mnhauke:sdr-devel/openSUSE_Factory_ARM/home:mnhauke:sdr-devel.repo
zypper refresh
zypper install nlohmann_json
For 16.0 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:mnhauke:sdr-devel/16.0/home:mnhauke:sdr-devel.repo
zypper refresh
zypper install nlohmann_json
For 15.6 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:mnhauke:sdr-devel/15.6/home:mnhauke:sdr-devel.repo
zypper refresh
zypper install nlohmann_json