I figured it out. If your keyboard is set to French numerical (an AZERTY keyboard) you see the Perspectives commands as command “pad” +n°. But you add the ABC (a QWERTY English keyboard) then when you’re in Omnifocus, you see command+n°. So basically, you have to add a QWERTY keyboard input in your System Preferences and then on the upper right menu board change to the QWERTY keyboard when you’re in Omnifocus when you create shortcuts. They work even if the AZERTY keyboard is used while in Omnifocus, but not when you create the shortcuts.