Sprwt walks you through a locked sequence before you can sell anything:

1. Choose a POS Device from a list of the reseller's active devices.
2. Enter your employee PIN code to sign in as a cashier.
3. If there's no cash drawer already open for that device, you're prompted to start a drawer with a starting cash amount.

Only after all three are satisfied does the checkout grid become usable. The device and drawer choices are remembered per browser (stored locally), but the employee PIN session is not — so a returning cashier on the same device/browser usually only has to re-enter their PIN, not re-pick the device or drawer.