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.
RPCTypeCheck(request.params, {
        UniValue::VSTR, 
        UniValue::VNUM, 
    });
    const NodeContext& node = EnsureAnyNodeContext(request.context);
    ChainstateManager& chainman = EnsureChainman(node);
    PeerManager& peerman = EnsurePeerman(node);
    const uint256& block_hash{ParseHashV(request.params[0], "blockhash")};
    const NodeId peer_id{request.params[1].getInt<int64_t>()};
    const CBlockIndex* const index = WITH_LOCK(cs_main, return chainman.m_blockman.LookupBlockIndex(block_hash););
    if (!index) {
        throw JSONRPCError(RPC_MISC_ERROR, "Block header missing");
    }
    
    
    if (node::fPruneMode && index->nHeight > WITH_LOCK(chainman.GetMutex(), return chainman.ActiveTip()->nHeight)) {
        throw JSONRPCError(RPC_MISC_ERROR, "In prune mode, only blocks that the node has already synced previously can be fetched from a peer");
    }
    const bool block_has_data = WITH_LOCK(::cs_main, return index->nStatus & BLOCK_HAVE_DATA);
    if (block_has_data) {
        throw JSONRPCError(RPC_MISC_ERROR, "Block already downloaded");
    }
    if (const auto err{peerman.FetchBlock(peer_id, *index)}) {
        throw JSONRPCError(RPC_MISC_ERROR, err.value());
    }
    return UniValue::VOBJ;
},
    };
}
static RPCHelpMan getblockhash()