// Change this
<button class="gdpr-agreement <?php echo $style ? '' . $style : 'btn-accent'; ?> btn-flat <?php echo esc_attr( $button_class ); ?>" type="button"><?php echo esc_html( $accept_button_text ); ?></button>

// To this
<button class="gdpr-agreement <?php echo $style ? '' . $style : 'btn-accent'; ?> btn-flat <?php echo esc_attr( $button_class ); ?>" type="button">YOUR TEXT HERE</button>