Custome fields not displayed

You have to add the code to your template to display the fields. They don’t automatically output to your page. Assuming you’re using the text field, you need to add the following:

<h2><?php the_field('heading'); ?></h2>

Chage the text ‘heading’ to the name of your custom field.

Normally, If it’s the home page, you can edit the template called front-page.php, or if it’s a post, you edit single.php and add the above code there.

You can read more about it here