curl --request POST \
  --url https://api.uniblock.dev/uni/v1/json-rpc?chainId=137 \
  --header 'content-type: application/json' \
  --data '{
    "id": 1,
    "jsonrpc": "2.0",
    "method": "eth_chainId",
    "params": []
  }'

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": "0x1"
}