Thanks for the reply.
I had misunderstanding how this plugin works, now I got it.
It works now
Just for other users if they see this topic in the future: You should go to each Category you created before or create after that, click on Subscribe green button and the plugin should work for you like me.
For example in my website I have 3 categories called Q/A, Free Discussion and Announcements. I should subscribe in all these three and then just wait for another user to create topic.
My website is: pythonforum.ir and as it's in Persian language, to acknowledge my mean I think it's better to use translators (sorry, I hope this sentence is not offensive, but if it is please pardon me and inform me).
I have created some Sections like Python 3 and Python 2 which are my issues now. Both sections have their own Q/A and Tutorials forums in which users can create topic.
But the issue is about breadcrumb that does not include and indicate the Section name.
If you go to https://pythonforum.ir/category/5/پرسش-و-پاسخ and https://pythonforum.ir/category/8/پرسش-و-پاسخ , you see in the breadcrumb that both have 'Home / Q/A' and if a user creates a topic in Python 2 forum for example, I cannot understand by seeing breadcrumb.
Is that an issue? Can I solve in Admin settings? I did not find any options for this.