How can I link a file in admin with a button?

Finally, I make it, the way without losing the access to WordPress environment:

add_action( 'edit_form_after_title', 'custom_button' );
function custom_button() {
$button = sprintf('<a href="https://wordpress.stackexchange.com/questions/273582/%1$s" class="button button-primary button-large">%2$s</a>', esc_url( add_query_arg( 'link' , true, get_the_permalink() ) ), 'Custom Button'
    );

    print_r($button);
}

Update:

Hint: Please make a function for validation the url for ssl and wrap get_the_permalink() inside it.