A simple approach:

for my $ref ( @records ) {
    if ($ref->{URL}) {
        print qq{<B>Webpage:</B> <A HREF="$ref->{URL}">$ref->{URL}</A>
+<br>};
    }
}
[download]

But I think you're asking for an approach that puts the check for URL in the foreach line:

for my $ref ( grep $_->{URL}, @records ) {
    print qq{<B>Webpage:</B> <A HREF="$ref->{URL}">$ref->{URL}</A><br>
+};
}
[download]

I combined the print statements into a single print of a single string, and used qq{} to avoid having to escape the double quotes.

That's two ways to do it...