...

my $token      = SOAP::Data->name('token' => 'value')->attr({xmlns => 'ns1'});
my $merchantId = SOAP::Data->name('merchantId' => 'value')->attr({xmlns => 'ns1'});


my %request = (
    'Amount'        => 'value',
    'CurrencyCode'  => 'value',
    'CustomerEmail' => 'value',
    #....
);

my @request_values = ();

foreach my $r (keys %request) {
    push @request_values,
         SOAP::Data->name($r => $request{$r})->attr({xmlns => 'ns2'});
}

my $request = (
    SOAP::Data->name('request' => \SOAP::Data->value(
            @request_values
        )
    )->attr({xmlns => 'ns1'})
);

my @setup_values = ();
push @setup_values, $token, $merchantId, $request;

my $setup = (
    SOAP::Data->name('Setup' => \SOAP::Data->value(
            @setup_values
        )
    )->attr({xmlns => 'ns1'})
);


# pass $setup as a param to the method to be called
...