How Can I Create A Form In WordPress For Subscribers To Alert Them about new Listing posted?

From this site – https://homekik.aminulhub.info/
Check out the “Be the first to know”. We r using a 27collective Listing theme to test the website.

My Client made the form in Contact Form 7. Now he wants this method work – when a subscriber subscribes through this form he/she will be notified about any new Listing posted of his chosen option.
Now I am not aware of any WordPress Form plugin which has this kind of feature or any Theme has this kind of method with listing alert.

Is there any WordPress Plugin or Theme with this method? Or any suggestion from u guys for alternative ideas to do something like this for my client.
I really need your help guys.

See this screenshot of that section-

Thanks In Advance