Translate string (w/ WPML plugin)

Hello, I’m trying to translate a string I added to ‘includes/loop-index.php’.

I’ve added another data-entry called ‘Article Source’ using ACF. I’m using this code to display it:

					_e( 'Article Source: ', 'avia_framework' );
					echo '<a href="';
					the_field('article_source');
					echo '">';
					the_field('article_source');
					echo '</a> '; 

I want ‘Article Source’ to be translatable.

How do I add the string to the po file that avia_framework is using? Or do I have it all wrong?

Thank you.