Is it possible for multiple managers to work in the service under different accounts?

It is possible at the Business subscription plan. You can configure several accounts for your employees with flexible permissions settings.

At other plans, the service provides only one account for the manager. With this account, 2 managers can work from different devices at the same time. In this case, they can simultaneously work with tables of orders, they can confirm and reject existing orders. However, they will not be able to add new orders simultaneously.