Selling online to Northern Ireland - XI number needed ?

Hi There. Im going to be selling via online shop to Northern Ireland and the EU. I am based solely in the UK (England) with no offices in the EU or Northern Ireland. It will be printed goods, leather goods, laser cut & engraved products, and possibly some wooden furniture. I have voluntarily registered for VAT, and will be applying for a GB EORI. I will be shipping using Royal Mail, DPD, or EVRI. The question is, do I need a XI EORI number as well as a GB one. I ask as its a bit confusing as all the information and help pages mention having a XI EORI number to send goods to Northern Ireland. Even the check if you need one page says you do (unless im filling in the details wrong). If I do need one, how do I get one when I don't have any premises in Northern Ireland and can't afford to appoint an economic operator from there being a small start up. Many thanks for the help.

Hi,
Please check below link for guidance, it covers when you do not need an EORI number that starts with XI:
Get an EORI number
Please check below guidance on what do you need to get an XI EORI and how to apply:
Apply for an EORI number
Thank you.