I am a mobile phone user of Telecom. How to open unconditional call forwarding by SMS?

Hello, taking telecommunications as an example, users need to open the call forwarding function. After opening, the call forwarding method is as follows:

Unconditional transfer setting method: *72+ area code+phone number+press the dial key (the area code is not needed to transfer the incoming call to the mobile phone number), and logout method: *720+ press the dial key.

No answer or shutdown transfer setting method: *92+ area code+phone number+press the dial key (the area code is not needed to transfer the incoming call to the mobile phone number), and cancellation method: *920+ press the dial key.

Busy transfer setting method: *90+ area code+phone number+press the dial key (the area code is not required for the incoming call transfer number), and cancellation method: *900+ press the dial key.