Twilio Narrowband SIM cards must be used in T-mobile-approved modules. For a list of modules that have been approved for use on their network, see T-mobile's IoT device certification site here:

https://iot.t-mobile.com/device-certification/#certified-modules

Notice: Twilio Narrowband SIMs use a different radio band than standard wireless phone SIM cards, and are unable to be used in standard mobile phones.