hi @warrag 
What is the version of Odoo you are using and what is the system windows or ubuntu ?
Have you followed all the instructions \\here

https://www.odoo.com/documentation/user/11.0/point_of_sale/overview/setup.html/

show this link 
https://github.com/odoo/odoo/issues/25007

the problem is fixed in this link
https://stackoverflow.com/questions/38683686/print-arabic-words-from-python-to-esc-pos-printer

Or you can bay this module 
https://www.odoo.com/apps/modules/10.0/arabic_receipt_pos/

Hi 

odoo v = 10

system = ubuntu

i follow all the instructions and receipt is printing but no Arabic letter