You'll need to provide a bit more information and context than that if you want assistance from the Community Forum.
Are you on a legacy membership plan with a limited mobile data allowance and you're approaching the allowance limit?
If so then when you use up your membership plan mobile data allowance you can buy a mobile data add-on to continue using mobile data for the remainder of the membership month.
If this is happening habitually then you might want to consider switching to the unlimited data €12.99 plan.
If that's not your issue then you'll need to explain/describe your issue more clearly and in more detail.
If you need to contact 48 support about this then see the links in my signature below.
