How do I change the wireless technology to LTE?

Could you please help me figure something out? So I bought my new Blackview phone (which I love) from AliExpress. When it arrived from China, it was added to my T-Mobile as my new phone with my same number. Problem is it does not go on line, like it's supposed to, with my mobile data. The reason is this: the wireless network technology where it's supposed to say LTE on the top of the phone next to the signal strength is actually set for what is used in China. Therefore, my mobile data will not connect. How can I change this to be on LTE? There has to be a way. Please help me I would appreciate it so very, very much. Thank you for your time.