To run a screener backtest, follow these steps:

Select the screener you wish to backtest from the Screeners section. You can also run backtests on screeners you've created under "My Screeners."

(Please note that certain parameters, such as Relative Returns, may not be backtestable due to limited historical data.)

Once you open the screener, click ‘Backtests’, as shown below. 

Now, set the start and end dates for the backtest period. Then choose the stock universe and the benchmark against which you want to run the backtest.

You can use the ‘Advanced’ option to configure additional preferences, add parameters, and choose the maximum number of stocks selected per period.

After setting your preferences, click ‘Run Backtest’ to see the results.