How to activate VoLTE in Vietnam via OnePlus 7T Pro

  1. bcphung
    Cupcake Dec 30, 2019

    bcphung , via OnePlus 7T Pro , Dec 30, 2019 :
    I am having my new 7T Pro, unfortunately, my country is not a target market for OnePlus.
    Now I'd like to have VoLTE support, can anyone show me the way?

    Thank you in advanced.