There are 3 steps after creating shortcut for terminal :

1. Name : e.g , "Launch Terminal"
2. command : Choose one of these : { GNOME Terminal: "gnome-terminal"

Xfce Terminal: "xfce4-terminal"

Konsole (KDE): "konsole"

Tilix: "tilix"

LXTerminal: "lxterminal" }

3.Your Shortcut : fn + f4