For openSUSE Tumbleweed run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:j-engel:samba-unstable/openSUSE_Tumbleweed/home:j-engel:samba-unstable.repo
zypper refresh
zypper install krb5
For 15.5 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:j-engel:samba-unstable/15.5/home:j-engel:samba-unstable.repo
zypper refresh
zypper install krb5
For 15.4 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:j-engel:samba-unstable/15.4/home:j-engel:samba-unstable.repo
zypper refresh
zypper install krb5