The following attempts to extract price data from “XBU6TFX4H46E,” a 2/7/20 QQQ 221 Call. However, the output is empty, which shouldn't be since I originally pulled the data for this specific option after calling GetOptionHistory on qb.AddOption("QQQ", Resolution.Minute). 

opt_from_str = qb.AddOption("XBU6TFX4H46E", Resolution.Minute)
single_symb_opt_history = qb.GetOptionHistory(opt_f_str.Symbol, datetime(2020,1,1,15,38,0), datetime(2020,1,1,15,41,0))
single_symb_opt_history.GetAllData()