wp_remote_request to url with port 8001 not woorking

I try to send a request with the function wp_remote_request and it is not accepted (Note the port at URL)

When I download the port it is accepted

Where's the problem?

tish is the code:

$args = array(
    'body' = array(
            'key' = 'value' 
    )
);
wp_remote_request('http://exemple.com:8001/page', $args);