Strange Error, IDE tells that I've missed to include the library, but I haven't!

This is my test code:

#include <Keyboard.h>

void setup() {
 Keyboard.begin();
 delay(2000);
 Keyboard.print("Test");
}

void loop() {
}

This is the Error:

Arduino: 1.8.8 (Linux), Board: "Arduino Nano, ATmega168"

/home/username/Arduino/simple_hid_test/simple_hid_test.ino: In function 'void setup()':
simple_hid_test:4:3: error: 'Keyboard' not found. Does your sketch include the line '#include <Keyboard.h>'?
   Keyboard.begin();
   ^
exit status 1
'Keyboard' not found. Does your sketch include the line '#include <Keyboard.h>'?

I have no idea why it doesn't works!
I did also try: #inlude "Keyboard.h" instead of the <>...

Coul'd anyone please help?

Did you install a Keyboard library through the Library manager?

It's installed (it's from the examples), but yeah, I checked it.

The Keyboard library can only be used with Arduino boards with native USB capabilities, such as Leonardo, Micro, Due, Zero, and MKR. The Arduino Nano you're compiling for does not have native USB capability, thus the error.

OK. Thanks! I should have tried to compile for different boards first... I'll keep that in mind next time before I post!

The best thing you could have done in this situation is to check the documentation for the Keyboard library:

These core libraries allow the 32u4 and SAMD based boards (Leonardo, Esplora, Zero, Due and MKR Family) to appear as a native Mouse and/or Keyboard to a connected computer.