There are a few different attempts at the turtle strategy on here, but none that I have seen thus far correctly follow the strategy as I know it. This version uses a stop order to trail out of the position by moving the stop order to match the exit channel or stoploss as the N*2( ema
of True Range * 2). This version of turtle strategy also uses stop orders for entry on either side in order to enter at optimal time. The ability
to specify a backtest period was borrowed from another script, I grabbed it so long ago I no longer remember from whom i borrowed it, if it was yours I will credit you if you PM me.
This version unlike others also allows you to specify a risk % so you only risk that percentage of your equity in a trade, as calculated from your stoploss.
Disclaimer: I have published several scripts in the past when i was first learning pinescript and they are all horrible please ignore those. I would delete them, but TV doesn't allow you to delete.