Pin an unexpected application, when the app has more than one desktop file

I started a pcmanfm-qt, then I pinned it to the dock, but I got a 'Desktop' icon. The same thing happened to qterminal and qterminal-drop.

/usr/share/applications/pcmanfm-qt.desktop

[Desktop Entry]
Exec=pcmanfm-qt %U
Name=PCManFM-Qt File Manager

/usr/share/applications/pcmanfm-qt-desktop-pref.desktop

[Desktop Entry]
Exec=pcmanfm-qt --desktop-pref=general
Name=Desktop

cutefishos / dock