Hi Louise,
Uniwell info is difficult to get so I don't have any for this model. There is a dealer who has the programming manual on the net for your model (lx5700. The 'F' just means flat keyboard type). If you need the manual, go here:
https://the-checkout-tech.com/manuals/cashregisters/Uniwell_LX-5600_LX-5700_LX-5750_Type_02_Programming_manual.html
Registerman
January 2019