gp-pay-per-word-i-mean-line.js

/**
 * Gravity Perks // Pay Per Word // Surprise, Pay Per Line!
 * https://gravitywiz.com/documentation/gravity-forms-pay-per-word/
 */
gform.addFilter( 'gpppw_word_count', function( wordCount, text, gwppw, ppwField, formId ) {
	// Pay per character instead of words.
	var words = text.split( '\n' );
	return words == null ? 0 : words.length;
} );

gp-pay-per-word-i-mean-line.php

<?php
/**
 * Gravity Perks // Pay Per Word // Surprise, Pay Per Line!
 * https://gravitywiz.com/documentation/gravity-forms-pay-per-word/
 */
add_filter( 'gpppw_word_count', function( $word_count, $words ) {
	$words = explode("\n", $words);
	return count( $words );
}, 10, 2 );