Hello Sir

Go to on google and search your font : https://fonts.google.com/?subset=arabic

Then update it's embedded  code in functions.php file.

I attached some screenshot to help you.

http://prntscr.com/n2h1x5

http://prntscr.com/n2h0t4

http://prntscr.com/n2h2g7

http://prntscr.com/n2h2mp

Thanks

Khelesh M

DexignZone