For openSUSE Tumbleweed run the following as root:
zypper addrepo https://download.opensuse.org/repositories/isv:SUSEInfra:Devel/openSUSE_Tumbleweed/isv:SUSEInfra:Devel.repo
zypper refresh
zypper install salt
For 15.5 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/isv:SUSEInfra:Devel/15.5/isv:SUSEInfra:Devel.repo
zypper refresh
zypper install salt
For 15.4 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/isv:SUSEInfra:Devel/15.4/isv:SUSEInfra:Devel.repo
zypper refresh
zypper install salt