Pressing the key at the left side of '1' in Arduino Keyboard Library

As I understand when we program the Arduino as a keyboard the HID works not by sending ASCII codes but by sending the physical location of the key, based on a US Layout. I, however, have a different layout and would like to send a keypress of the left uppermost key, the key on the left of number '1'. I have tried sending:

Keyboard.press('`');

Keyboard.press('"');

Keyboard.press('§');

but none of them seem to work. Any suggestions ?

Apparently this key is listed as "0x64 Keyboard Non-US \ and |" (from here) so this worked:

Keyboard.write(0x64 + 0x88);