Should VAT be charged on a invoice for NI sale to the ROE

When a Northern Ireland NI business invoices sells goods to a business in the Republic of Ireland ROI should VAT be added to the sales invoice. Or would the sale be zero-rated for VAT? (If you could share any government HMRC guidance or notice that states/explains this) - thanks

Hi,
Please see the guidance below:
VAT on movements of goods between Northern Ireland and the EU 3. Supplies to VAT registered customers
Thank you.