Thanks Sharon
I'm working with your solution but I do not get nothing yet.
you say "Set the post ID to $post_id inside your function"
I'm not sure where I have to make that.
I continue trrying with your solution to see if I get it.
On my other proves...
On the function the code get the elements like this
$post_title = $instance->get( 'post' )->post_title;
also I try with
$singleee = $instance->get( 'post' )->single-post-thumbnail;
or
$singleee = $instance->get( 'post' )->the_post_thumbnail;
But I do not get nothing. I think that the problem is how all in one event calendar get the image.
I continue trying to get it.