If your market data provider doesn't support historical Bid-Ask data you will see all historical trades on the Bid side.
Eg. Forex and NSE markets don't provide historical Bid-Ask data.
These indicators can be adjusted for historical non-BidAsk data: mzFootprint, mzVolumeProfile, mzBigTrade, mzVolumeDelta. Choose 'Orderflow – Calculation mode' = UpDownTick.
Hybrid mode and Indian Market (NSE)
Indian Market data providers (eg. Accelpix) don’t translate historical Bid-Ask data so far. Indian users must set the value for ‘Orderflow – Calculation mode’ = Hybrid. The Hybrid mode uses UpDownTick calculation for historical data and BidAsk calculation for real-time data, which is 100% accurate. Read more.
Note, when you reload Ninja script, all collected data are becoming HISTORICAL and UpDownTick mode is applied. All prior live data-based (bid/ask) indicator's plots are more or less different now. We don't recommend doing this during the trading session. Open Ninja at the beginning of a trading session if you need 100% accurate order flow.