For ECSs running Windows, the following characters cannot be input normally: ~ `
To input these characters, use either of the following methods:

Method 1: Click AltGr on the VNC page and then press the suitable key on the keyboard twice.

Method 2: Press AltGr+~(`)+Space.
For ECSs running Windows and Linux, the following characters cannot be input normally: #, {, [, |, \, ^, @, ], }, ¤, €
To input these characters, do as follows:

Click AltGr on the VNC page and then press the suitable key on the keyboard.
No L'accent circonflexe or Le tréma can be input on characters A, E, I, O, and U using the physical keyboard.
To input these characters, do as follows:

Click ^: on the VNC page and then press the suitable key on the keyboard.
No character can be input using the French keypad.
To input these characters, do as follows:

Use the French keyboard.

Why Cannot I Use the French Keyboard to Enter Characters When I Log In to an ECS Using VNC?