At the Business plan - multiple, at other plans - only one.
When the manager starts insert a new reservation, the system creates a new order for it in the "Cart" status.
The manager fills in the data and changes the status to "Confirmed".
The order is created.
Now he can create a new order, which will also initially receive the "Cart" status.
If you have chosen a Free or Professional subscription plan, then you have only one manager.
The manager has only one "Cart" in the system.
So you can not simultaneously create two different orders form different devices.
Therefore, it is not recommended to use the system with multiple managers at these plans.
At the Business plan you can create multiple employees.
Each employee will work with his own "Cart".
Moreover you can flexibly configure permissions and tables for each employee.