For SLE 15 SP6 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:yfjiang:gnome:stable45:extradep-wo-python/SLE_15_SP6/home:yfjiang:gnome:stable45:extradep-wo-python.repo
zypper refresh
zypper install desktop-file-utils
For SLE 15 SP5 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:yfjiang:gnome:stable45:extradep-wo-python/SLE_15_SP5/home:yfjiang:gnome:stable45:extradep-wo-python.repo
zypper refresh
zypper install desktop-file-utils