openSUSE Leap 15.6 の場合は、 root で下記のコマンドを実行してください:
zypper addrepo https://download.opensuse.org/repositories/devel:openQA:GitHub:os-autoinst:openQA:PR-6350/openSUSE_Leap_15.6/devel:openQA:GitHub:os-autoinst:openQA:PR-6350.repo
zypper refresh
zypper install openQA
SLE 15 SP6 Backports の場合は、 root で下記のコマンドを実行してください:
zypper addrepo https://download.opensuse.org/repositories/devel:openQA:GitHub:os-autoinst:openQA:PR-6350/SLE_15_SP6_Backports/devel:openQA:GitHub:os-autoinst:openQA:PR-6350.repo
zypper refresh
zypper install openQA