Open GBPUSD chart, M15 tf, check the closing price of the 15M bar that starts at 00:15GMT and closes at 00:30GMT - this is "Base Price". Then place two pending orders: 50 pips above and 50 pips below the base price. TP and SL for both orders is 20pips. Note: if one of them opened, delete the second order, if none of them opened in the next 24 hours, you should delete both orders at 00:00GMT