Add iCloud Mail Custom Domain in Outlook

This morning I added my custom domain to iCloud Mail and this is all working fine. However, I can't seem to add this email address to Outlook.

When I try to get my settings automatically fetched it asks me to enter IMAP and SMTP details. This tutorial doesn't work for me: https://support.microsoft.com/en-au/office/add-an-icloud-email-account-to-outlook-4aed8b3d-3c68-4743-8973-f6bd1c56e040

I tried setting up an App-Specific Password, as my username I enter my custom domain email address and I use the following settings for IMAP and SMTP but it can't authenticate my credentials: iCloud Mail server settings for other email client apps - Apple Support

Anyone has any suggestions on how to add my custom email address from iCloud Mail to Outlook?