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.
{
    return RPCHelpMan{"getblockcount",
                "\nReturns the height of the most-work fully-validated chain.\n"
                "The genesis block has height 0.\n",
                {},
                RPCResult{
                    RPCResult::Type::NUM, "", "The current block count"},
                RPCExamples{
                    HelpExampleCli("getblockcount", "")
            + HelpExampleRpc("getblockcount", "")
                },
        [&](const RPCHelpMan& self, const JSONRPCRequest& request) -> UniValue
{
    ChainstateManager& chainman = EnsureAnyChainman(request.context);
    LOCK(cs_main);
    return chainman.ActiveChain().Height();
},
    };
}
static RPCHelpMan getbestblockhash()