How to set it so that others can't call in when it is turned on?

You can try to enter **2 1*888888# and press the dial key to turn on the call forwarding function of this machine. After the phone is turned on, someone who calls you will be transferred to the empty number of 888888, so that other phones can't get in. Here are the relevant steps:

1. Just enter * * 2 1 * 8888888 # on the phone dialing interface of Android or Apple iOS1system, and press dial to activate call forwarding. 888888 is the forwarding number. Because this number doesn't exist, others can't call your mobile phone.

2. The method of cancellation is also very simple. Just dial ##2 1# and then dial again to cancel the access of the received phone again.