Netfile Access Code (NAC)

I have never used Netfile before (always paper returns) and I do not find a NAC in my Notice of Assessment nor in my CRA online account.  Besides the Tax Return I need to submit a T1135, hopefully electronically, as well.

 

I am going to use the downloaded Premier software.

 

Do I need a NAC as a first time Netfile user?   How/where can I get it?   Any other suggestions towards my first use of online submission?
Thank you!