DFR0063 I2C LCD Datasheet

I would like to use this LCD with I2C bus but cannot use arduino Wire library.
Why cannot we communicate in 8bit mode?

in LiquidCrystal_I2C.cpp it mentions a datasheet to implement;
Line 64: // SEE PAGE 45/46 FOR INITIALIZATION SPECIFICATION!
// according to datasheet...
Where is this datasheet, can you post a link?

Thanks
MB