There's no "roaming activation".
On the general issue of roaming, the usual generic advice applies...
Unfortunately many people still seem to have problems with roaming abroad on 48 for some reason.
(On the other hand all the people who have no problems don't post to report their positive experiences!)
If your SIM predates January 2023 then a replacement may mitigate or eliminate roaming problems:
It may be worthwhile reviewing these two threads in case any of the suggestions help to avoid roaming problems:
If mobile data doesn't work while roaming abroad in countries where it's supported then check that your APN settings are configured correctly:
In some countries an active membership plan and cash credit to pay for mobile data usage are required.
If you have returned to Ireland from roaming abroad and are having problems using the 48 network/calls/texts/mobile data then see this key post, in particular the section titled "Returned Home?":
If you still have problems then you'll probably need to contact 48 support for further assistance.
See the links in my signature below for the different ways to contact 48 support.
