use strict;
    use warnings;
    use Tk;
    use Tk::PNG;
    my $png = 'myicon.png';
    my $mw = Tk::MainWindow->new();
    my $icon = $mw->Photo(-file => $png);
    my $btn = $mw->Button(
        -image => $icon,
    );
    $btn->pack();
    $mw->MainLoop();

##</code><code>##

couldn't open "myicon.png": no such file or directory