I want to send a message to a french number

[dalyer]

I presume that you mean an SMS text message?

International calls and texts are not covered by membership plan call minutes/text message allowances.

Those allowances only cover calls/texts to Irish mobiles and landlines (and calls to Northern Ireland landlines dialled using the 048 prefix).

To make international calls or send international texts you need an active membership plan and also cash credit on your account to pay for the international calls/texts.

See here: 

• https://community.48.ie/t5/The-Knowledge-Base/International-Calls-amp-Texts/ta-p/53116
• https://48.ie/charges/international-calls

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