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.
},
        [&](const RPCHelpMan& self, const JSONRPCRequest& request) -> UniValue
{
    UniValue ret(UniValue::VOBJ);
    const CBlockIndex* pindex{nullptr};
    const CoinStatsHashType hash_type{request.params[0].isNull() ? CoinStatsHashType::HASH_SERIALIZED : ParseHashType(request.params[0].get_str())};
    bool index_requested = request.params[2].isNull() || request.params[2].get_bool();
    NodeContext& node = EnsureAnyNodeContext(request.context);
    ChainstateManager& chainman = EnsureChainman(node);
    Chainstate& active_chainstate = chainman.ActiveChainstate();
    active_chainstate.ForceFlushStateToDisk();
    CCoinsView* coins_view;
    BlockManager* blockman;
    {
        LOCK(::cs_main);
        coins_view = &active_chainstate.CoinsDB();
        blockman = &active_chainstate.m_blockman;
        pindex = blockman->LookupBlockIndex(coins_view->GetBestBlock());
    }
    if (!request.params[1].isNull()) {
        if (!g_coin_stats_index) {
            throw JSONRPCError(RPC_INVALID_PARAMETER, "Querying specific block heights requires coinstatsindex");
        }
        if (hash_type == CoinStatsHashType::HASH_SERIALIZED) {
            throw JSONRPCError(RPC_INVALID_PARAMETER, "hash_serialized_2 hash type cannot be queried for a specific block");
        }
        if (!index_requested) {
            throw JSONRPCError(RPC_INVALID_PARAMETER, "Cannot set use_index to false when querying for a specific block");
        }
        pindex = ParseHashOrHeight(request.params[1], chainman);