By default Blender doesn't have the ability to write Farsi or Arabic text. This plugin enables you to write Farsi or Arabic text and these are the steps:
1) Download the Plugin. 2) Open Blender go to Edit > Preference and click on install an addon. 3) Select the plugin zip file. 4) Find your plugin in the list ( You can use search and write plugin name). 5) Check the box 6) Create a text by going to Add > Text. 7) Press Ctrl+1 to active the plugin 8) Enjoy writing!