eth_blockNumber

curl --request POST \
  --url https://{network}.s.chainbase.online/v1/{api-key} \
  --header 'Content-Type: application/json' \
  --data '{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "eth_blockNumber",
  "params": []
}'

{
  "id": 1,
  "jsonrpc": "2.0",
  "result": "<string>"
}