the command "bitcoin-cli getblockstats 0000000000000000000c61ff8f761ce509fc8901d3c22d61fec89637042ea2ba" does not work.

It displays "error: Error parsing JSON:0000000000000000000c61ff8f761ce509fc8901d3c22d61fec89637042ea2ba"

but it should display the block stats like the documentation says.

also bitcoin-cli getblockstats 0 does not work. block number must be at least 1 to work. But blocks start at 0.

tested with 0.20.1 on freebsd, another user on IRC acknowledged the problem.
template<typename T, typename Tk, typename... Args>
static inline bool SetHasKeys(const std::set<T>& set, const Tk& key, const Args&... args)
{
    return (set.count(key) != 0) || SetHasKeys(set, args...);
}
static constexpr size_t PER_UTXO_OVERHEAD = sizeof(COutPoint) + sizeof(uint32_t) + sizeof(bool);
static RPCHelpMan getblockstats()
{
    return RPCHelpMan{"getblockstats",
                "\nCompute per block statistics for a given window. All amounts are in satoshis.\n"
                "It won't work for some heights with pruning.\n",
                {
                    {"hash_or_height", RPCArg::Type::NUM, RPCArg::Optional::NO, "The block hash or height of the target block", RPCArgOptions{.type_str={"", "string or numeric"}}},
                    {"stats", RPCArg::Type::ARR, RPCArg::DefaultHint{"all values"}, "Values to plot (see result below)",
                        {
                            {"height", RPCArg::Type::STR, RPCArg::Optional::OMITTED, "Selected statistic"},