Thanks to you I tried this on my functions.php
It worked, but also had to get the ID of the page, in my case 4.
add_action( 'woocommerce_before_main_content', 'woocommerce_category_image', 2 );
function woocommerce_category_image() {
if ( is_product_category() ){
global $wp_query;
$cat = $wp_query->get_queried_object();
$thumbnail_id = get_term_meta( $cat->term_id, 'thumbnail_id', true );
$image = wp_get_attachment_url( $thumbnail_id );
if ( $image ) {
echo '<div class="category-image"><img src="' . $image . '" alt="' . $cat->name . '" /></div>';
}
}
if ( is_shop() ){
$target_post_id = '4';
$image = wp_get_attachment_url(get_post_thumbnail_id($target_post_id));
echo '<div class="category-image"><img src="' . $image. '" alt="' . $target_post_id->name . '" /></div>';
}
}