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.
{RPCResult::Type::STR_HEX, "hex", "The raw public key script bytes, hex-encoded"},
                    {RPCResult::Type::STR, "address", true, "The Bitcoin address (only if a well-defined address exists)"},
                    {RPCResult::Type::STR, "type", "The type (one of: " + GetAllOutputTypes() + ")"},
                }},
            }},
        }},
    }
};
static RPCHelpMan getblock()
{
    return RPCHelpMan{"getblock",
                "\nIf verbosity is 0, returns a string that is serialized, hex-encoded data for block 'hash'.\n"
                "If verbosity is 1, returns an Object with information about block <hash>.\n"
                "If verbosity is 2, returns an Object with information about block <hash> and information about each transaction.\n"
                "If verbosity is 3, returns an Object with information about block <hash> and information about each transaction, including prevout information for inputs (only for unpruned blocks in the current best chain).\n",
                {
                    {"blockhash", RPCArg::Type::STR_HEX, RPCArg::Optional::NO, "The block hash"},
                    {"verbosity|verbose", RPCArg::Type::NUM, RPCArg::Default{1}, "0 for hex-encoded data, 1 for a JSON object, 2 for JSON object with transaction data, and 3 for JSON object with transaction data including prevout information for inputs"},
                },
                {
                    RPCResult{"for verbosity = 0",
                RPCResult::Type::STR_HEX, "", "A string that is serialized, hex-encoded data for block 'hash'"},
                    RPCResult{"for verbosity = 1",
                RPCResult::Type::OBJ, "", "",
                {
                    {RPCResult::Type::STR_HEX, "hash", "the block hash (same as provided)"},
                    {RPCResult::Type::NUM, "confirmations", "The number of confirmations, or -1 if the block is not on the main chain"},
                    {RPCResult::Type::NUM, "size", "The block size"},
                    {RPCResult::Type::NUM, "strippedsize", "The block size excluding witness data"},
                    {RPCResult::Type::NUM, "weight", "The block weight as defined in BIP 141"},