I want to buy more roaming but I don’t know how to

[dalyer]

I presume that you mean more roaming mobile data?

If so then see here:

• https://community.48.ie/t5/The-Knowledge-Base/Roaming-Using-your-Phone-Abroad/ta-p/53115

Can I buy extra Data for EU/UK roaming? 

Yes! If you've used your EU/UK data roaming allowance or simply just want more, then the 1GB data add-on can be used in Ireland and in the EU/UK when you’re on a plan that has roaming included. To purchase your add on, simply Log in to your My48 >> Flexi Data >> Add ons, or just click here.

If you are referring to something else then please clarify what it is.

If you need to contact 48 support about this then see the links in my signature below.