Hi madfer & welcome to the community!
In order to function, your phone must be compatible with the Fido network, which uses GSM, UMTS, HSPA and HSPA+ at 850 MHz and 1900 MHz. To access LTE network, the phone must be compatible with:
Since your phone is unlocked, it is very possible that you will need to configure your settings in order to use data. Here's how to do it on an Android phone:
MMS (Picture & Video Messaging Settings):
NOTE: The created APN will show up on the APNs screen. To activate the APN, tap on the radio button located in front of APN.
Hope this helps!