There is an error in the documentation (I thought I had already fixed that): any declaration that has a subref in it must be written like this:

tagname => {
    code => sub { ... },
},
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I forgot this because the tagname is 'code', and my brain probably refused to duplicate a word. Please report, if you find any further bugs or documentation issues.

edit: so that means it must be:

my $p = Parse::BBCode->new({
    tags => {
        ...
        code => {
            code => sub {
                my ($parser, $attr, $content, $attribute_fallback) = @
+_;
            },
        }, ...
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