getFirstAvailableBlock

curl --request POST \
  --url 'https://mainnet.helius-rpc.com/?api-key=' \
  --header 'Content-Type: application/json' \
  --data '
{
  "jsonrpc": "2.0",
  "id": "1",
  "method": "getFirstAvailableBlock"
}
'

{
  "jsonrpc": "2.0",
  "id": "1",
  "result": 250000
}