@pitaj Thanks for the reply.
Yes the images were correct as you have said, although that will not matter when I have finished explaining.
So. Using the drop down method for iCloud will work.
I use an iCloud address for my own personal email and as I did not want to use that in my forum I had created an alias iCloud email. I also created an app specific password for NodeBB on my Apple ID page.
When setting up in NodeBB my thoughts were (stupid now) were that I need to setup and sign in using the alias email I had created along with the new app specific password. Not the case.
For anyone else that might try (or as dumb as me) then you can put your alias email address at the top here so it shows it came from that address. If anyone replies then of course it will go to my alias inbox. Fine with me.
Enable SMTP Transport, select iCloud as your service and use your MAIN iCloud email address (not the alias as I did) as your username and the app specific password you just created. All will work. Trust me.
In my defense to start with it was saying email successfully sent although nothing came. Then trying smtp settings you see what i got above. In the end it was all very simple and although I am sure some would have known that maybe some would not. We all have had the slap on the forehead moments and this was one for me. Hopefully it MAY help someone out in the future.
Big thanks to @PitaJ
Appreciate the time.