tesseract ocr version 4

hi

i want to use tesseract version 4 cause i need persian language

 here is my code

 

Bitmap img = new Bitmap(@"C:\****\ConsoleApp4\ConsoleApp4\Untitled.png");
            Tesseract.TesseractEngine engine = new Tesseract.TesseractEngine(@"****\ConsoleApp4\ConsoleApp4\tessdata", "fas");

but i got this error

 

Error opening data file C:\****\ConsoleApp4\ConsoleApp4\tessdata/fas.traineddata
Please make sure the TESSDATA_PREFIX environment variable is set to your "tessdata" directory.
Failed loading language 'fas'
Tesseract couldn't load any languages!

 

can anyone help me?