Remove xfce4-panel

 $ sudo apt remove xfce4-panel
[sudo] password for dhwan:
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
The following packages were automatically installed and are no longer required:
  exo-utils libexo-2-0 libexo-common libgarcon-1-0 libgarcon-common
  libgarcon-gtk3-1-0 libxfce4panel-2.0-4 libxfce4ui-2-0 libxfce4ui-common
  libxfce4util-bin libxfce4util-common libxfce4util7 libxfconf-0-3 xfconf
Use 'sudo apt autoremove' to remove them.
The following packages will be REMOVED:
  xfce4-panel
0 upgraded, 0 newly installed, 1 to remove and 4 not upgraded.
After this operation, 3.849 kB disk space will be freed.
Do you want to continue? [Y/n] y
(Reading database ... 300046 files and directories currently installed.)
Removing xfce4-panel (4.16.3-1) ...
Processing triggers for desktop-file-utils (0.26-1ubuntu3) ...
Processing triggers for hicolor-icon-theme (0.17-2) ...
Processing triggers for gnome-menus (3.36.0-1ubuntu3) ...
Processing triggers for man-db (2.10.2-1) ...
Processing triggers for mailcap (3.70+nmu1ubuntu1) ...
Processing triggers for bamfdaemon (0.5.6+22.04.20220217-0ubuntu1) ...
Rebuilding /usr/share/applications/bamf-2.index...