In the previous version of Odoo, the PosBox was used to integrate hardware with the point-of-sale application. In version 12, the IoT Box was introduced and this can be used with a point of sale application like the PosBox. In order to use the IoT Box in a point of sale application, you have to connect the IoT Box with the Odoo instance. If you don't know how to connect the IoT Box, follow the Adding the IoT Box to Odoo recipe. Once you have connected the IoT Box with Odoo, you will be able to select the IoT Box in the point of sale application, as shown in step 2.

Here, you can select the hardware you want to use in the point of sale session. After saving the change, if you open the point of sale session, you will be able to use the enabled hardware in the point of sale. If you enabled specific hardware from the settings but the hardware is not connected to the IoT Box, you will see the following warning in the top bar: