For openSUSE Leap 15.6 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/devel:languages:php:php81/openSUSE_Leap_15.6/devel:languages:php:php81.repo
zypper refresh
zypper install php8
For openSUSE Leap 15.5 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/devel:languages:php:php81/openSUSE_Leap_15.5/devel:languages:php:php81.repo
zypper refresh
zypper install php8
For SLE 15 SP6 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/devel:languages:php:php81/SLE_15_SP6/devel:languages:php:php81.repo
zypper refresh
zypper install php8
For SLE 15 SP5 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/devel:languages:php:php81/SLE_15_SP5/devel:languages:php:php81.repo
zypper refresh
zypper install php8
For SLE 15 SP4 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/devel:languages:php:php81/SLE_15_SP4/devel:languages:php:php81.repo
zypper refresh
zypper install php8
For SLE 15 SP3 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/devel:languages:php:php81/SLE_15_SP3/devel:languages:php:php81.repo
zypper refresh
zypper install php8