No Page Comment is a set it and forget it plugin.
If you want comments disabled on pages, you can go to Settings > Discussion and then uncheck “Allow people to post comments on new articles”. This will make it so the default is unchecked for every new post and page you create.
If you have a blog and still want them enabled on new posts, then you will need to leave that checked, and just have to remember to disable them manually when you create a new page. You can manually disable them by editing your discussion settings on each new page. To be able to see the discussion settings for an individual page, click on the Screen Options tab at the top right when adding or editing a page. Then check the Discussion box (this will make is so the discussion settings box is always available and you won’t have to do this step again). Scroll down to the bottom of the page and you should see the new discussion settings. Then uncheck Allow Comments.
There is no native way to set it and forget it on a single post type in WordPress, such as only pages, which is why I developed No Page Comment. Before I developed it, I just had to remember to uncheck Allow Comments on every page I created.