Para openSUSE Leap 15.4 ejecute lo siguiente como root:
zypper addrepo https://download.opensuse.org/repositories/GNOME:STABLE:41/openSUSE_Leap_15.4/GNOME:STABLE:41.repo
zypper refresh
zypper install NetworkManager-openvpn
Para openSUSE Leap 15.3 ejecute lo siguiente como root:
zypper addrepo https://download.opensuse.org/repositories/GNOME:STABLE:41/openSUSE_Leap_15.3/GNOME:STABLE:41.repo
zypper refresh
zypper install NetworkManager-openvpn
Para SLE 15 SP4 ejecute lo siguiente como root:
zypper addrepo https://download.opensuse.org/repositories/GNOME:STABLE:41/SLE_15_SP4/GNOME:STABLE:41.repo
zypper refresh
zypper install NetworkManager-openvpn