change date format to UK

hi there,
I need to change the date format to the UK.

I have tried to change it in carousel.class.php:

9 => sprintf(
esc_html__( ‘Carousel scheduled.’, ‘responsive-posts-carousel’ ),
// translators: Publish box date format, see http://php.net/date
date_i18n( esc_html__( ‘j M, Y @ G:i’, ‘responsive-posts-carousel’ ), strtotime( $post->post_date ) )
),

but it didn’t work.

The page I need help with: [log in to see the link]