Once you enable Cash Tracking (Or tracking of other payment types) a screen shown below will appear before an Employee enters a sale when they first log in.

When the employee logs out they will get a screen asking them to reconcile the amount that should be in the register.

To add cash to the register, Click on the "..." dropdown menu from the sales interface and select "Add Cash to Register"

A screen will appear where you can log how much cash was entered into the cash drawer:

Enter the amount and and an optional comment, and then click Submit.

To remove cash to the register, Click on the "..." dropdown menu from the sales interface and select "Remove Cash to Register"

A screen will appear where you can log how much cash was removed from the cash drawer:

Enter the amount and and an optional comment, and then click Submit.

To close the register, Click on the "..." dropdown menu from the sales interface and select "Close Register"

A screen will appear where you can also check how much cash the cash drawer should have. You can log how many of each type of denomination are in the register and it will reconcile the amount with the expected amount. when click submit it closes the register. You can also log out without closing the register.