An authentication server may, in a case where a communication state between the authentication server and a management server is a non-connecting state, send first authentication information to an external device. A printer may, in a case where a communication state between the printer and the management server changes from a communication-enabled state to a communication-disabled state, shift a state of the printer from a first permission state to a first prohibition state, while the state of the printer is the first prohibition state, accept an input of second authentication information from a user; and, in a case where the input of the second authentication information is accepted and the second authentication information matches the first authentication information, shift the state of the printer from the first prohibition state to a second permission state.