Have you read these posts?
https://community.48.ie/t5/The-Knowledgebase/The-Roaming-Troubleshooting-Guide/ta-p/52179
https://community.48.ie/t5/Internet/How-to-fix-no-network-service-when-roaming/td-p/56352
Bear in mind that data roaming only works in Europe.
Are you having a specific problem?
If so, maybe you could describe it?
While you're here, check out our "Featured Topics" below.
Our Troubleshooting Guide and Knowledgebase contain help and support articles and popular questions to help you as a 48 customer.