Wordpress + phpbb + subdomain, how to link everything?

Question

phpBB

There is a site on WordPress. I want to make a forum on it, I installed the phpbb plugin
But, I want the forum to be here
forum.site.ru
How to implement this, I don’t want to put the engine separately on a subdomain, but I also want the base to be common ..

Answer 1

And I would do it separately, and even spread the forum and the site for different users, what is the problem with making the database separately, is there any connection between the forum and the site?