For openSUSE Leap 15.6 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/devel:openQA:GitHub:os-autoinst:os-autoinst:PR-2682/openSUSE_Leap_15.6/devel:openQA:GitHub:os-autoinst:os-autoinst:PR-2682.repo
zypper refresh
zypper install os-autoinst
For SLE 15 SP6 Backports run the following as root:
zypper addrepo https://download.opensuse.org/repositories/devel:openQA:GitHub:os-autoinst:os-autoinst:PR-2682/SLE_15_SP6_Backports/devel:openQA:GitHub:os-autoinst:os-autoinst:PR-2682.repo
zypper refresh
zypper install os-autoinst