activación

Do you have a current activated sim if so move the sim from the old phone to the new one.

Unless you are still a Sprint customer.  Phones don't require activation.  As mentioned, remove the SIM from your old device and put that SIM in your new device.  

how do you activate a N200 5G on an existing line with a broken Pixel 3 (eSim)?

Teyang wrote:

how do you activate a N200 5G on an existing line with a broken Pixel 3 (eSim)?

You purchase a new pSIM and have Customer Care or an employee at a T-Mobile Store activate the pSIM for you with the eSIM number, which will disable the eSIM.

thanks for the information.

Basically, there is no way to do this on my own and without help from T-mobile rep. I remember being able to do that with Sprint.