Embed /blog/index.php into current site

I have scoured through over 80 posts with similar topics but i still cant find a solution.

All I want to do is take my site: https://www.domain.com/blog.php and “include” the index page from /blog/index.php.

I tried to insert the following code in my blog.php page in the root level of the server.

<?include(‘/blog/index.php’);?>
or
<?include(‘./blog/index.php’);?>

is what I am trying to do possible?? I already setup exactly the way I want /blog/index.php to look when I incorporate it into my blog.php page.