How to get full book?

[iccicci]

Hi all,

I'm trying to analyze how data from this page changes:
https://www.bitfinex.com/funding-book/?pair=ETH

The most close API call I found is:

  await ws.subscribeOrderBook("fETH", "P0", "250");

but being the full book longer than 250 entries I get only a partial result; while if I try to request more than 250 lines I immediately get an "length: invalid" error.

So, which is the right call to get the full book?

Thank you