/usr/share/dbus-1/services/org.freedesktop.portal.IBus.service is in ibus 1.5.17-3ubuntu4.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 | [D-BUS Service]
Name=org.freedesktop.portal.IBus
Exec=/usr/lib/ibus/ibus-portal
|