Add directional arrow key

[Spr1ngLif3]

Please can you add directional arrow to the key?

[FunctionalJerk]

Are you talking about these symbols: ←→↓↑ or about the keys on the keyboard?
Case 1 just type them out or declare a function that does it for you (alt + 24..27).
case 2 they're in the library. Maybe you're looking for usage-IDs for the keypad-keys?
Either way, read into the source code of this library.

[CohenMurray]

In the DigiKeyboard.h there are no definitions for the right, up and down keys. You can edit the file and add these 3 lines
#define KEY_ARROW_RIGHT 0x4f
#define KEY_ARROW_UP 0x52
#define KEY_ARROW_DOWN 0x51

these are the scan codes for the missing keys.
just copy paste them into your existing DigiKeyboard.h file