With “frontend” you mean the public facing website? Or the admin area? Because all the text field does in the templates is output the text, so, if you need a class you need to wrap the output with an element:
<div class="example"><?php the_sub_field('episode_explanation'); ?></div>
And if you need a unique identifier you can use get_row_index() and add it as ID or class:
<div class="example" id="ex<?= get_row_index() ?>"><?php the_sub_field('episode_explanation'); ?></div>
