SELFBLUE. Added the new feature “Machine lock” to create privileged groups of users

With the “Machine lock” feature you can limit the use of a vending machine exclusively to a group of authorized users. For this, when creating the machine on the control panel, a QRcode is generated. Only users who scan the QRcode will be enabled to use that machine.
You can create up to 3 different groups, so, for example, if there are 3 vending machines in the same location, each of the machines can be reserved for a different group.
If, when creating the machine on the control panel, the “All” option is set, that machine can be used by all users.