First and foremost, you would need to have roaming enabling on your device, and you would need to have a roaming capable rate plan! Can you tell me what plan and what device you are using?
Hey sereed! I'm not sure if you're still in Costa Rica (what an awesome vacation that would be if you are!) but I wanted to check in with you and make sure you were able to either get this working for your current trip, or to see if we need to troubleshoot this with you before you travel again. How is everything going? Do you still have questions about roaming?