Huawei Y9 2019 Wi-fi calling option does not appear in settings

[Chamullo]

I have a Huawei Y9 and would like to use wi-fi calling but the setting does not appear under Settings > Wireless and Networks > Mobile Networks as the official manual states that it should.

I am connected to a wi-fi network, my carrier is Telstra Australia who does support wi-fi calling (used it with my old phone).

I have tried restarting.

Any ideas?
Thanks!