Need help customizing a purchased theme

Hi, I’m setting up a WP site for a non-profit and I’ve run into a little problem.
The problem is that the theme we are using has a Blog feature that only shows excerpts of posts (when you click on them you can see the full post). My problem is that I want the Blog page to show the full posts instead without having to go to the actual post.
From what I can tell there is a blog.php page template that calls and loops the blog posts and displays excerpts. Then there is a post.php file that is associated with the actual posts.
I know there must be a way to change the code somewhere to do what I want it to do, unfortunately I don’t know much about PHP.
I can show you the files if you need them, I would really appreciate the help.
The page in question is https://www.theleastamongus.org/news/