Para openSUSE Slowroll execute o seguinte como root:
zypper addrepo https://download.opensuse.org/repositories/home:mmanu84:php8:php84/openSUSE_Slowroll/home:mmanu84:php8:php84.repo
zypper refresh
zypper install php8
Para openSUSE Factory execute o seguinte como root:
zypper addrepo https://download.opensuse.org/repositories/home:mmanu84:php8:php84/openSUSE_Factory/home:mmanu84:php8:php84.repo
zypper refresh
zypper install php8
Para 15.6 execute o seguinte como root:
zypper addrepo https://download.opensuse.org/repositories/home:mmanu84:php8:php84/15.6/home:mmanu84:php8:php84.repo
zypper refresh
zypper install php8