Order a free SIM Activate your 48 SIM
Yes it should work
But be aware that many people have had problems getting data working while roaming in the EU on a Guido membership so if you have the same problem you'll need to contact 48 support.
Also you seem to be using an iPhone in which case you should be aware of this issue due to the stupid way that Apple do things.
Hope this helps.
Did that help at all @patriciagallagher?