For openSUSE Tumbleweed run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:AndnoVember:LXQt/openSUSE_Tumbleweed/home:AndnoVember:LXQt.repo
zypper refresh
zypper install picom-conf
For 15.5 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:AndnoVember:LXQt/15.5/home:AndnoVember:LXQt.repo
zypper refresh
zypper install picom-conf
For 15.4 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:AndnoVember:LXQt/15.4/home:AndnoVember:LXQt.repo
zypper refresh
zypper install picom-conf