curl https://site1.moralis-nodes.com/mantle/:apiKey \
  -X POST \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc": "2.0", "method": "eth_getBlockTransactionCountByNumber", "params": ["0xe8"], "id": 1}'

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": "0x0"
}