From what I gathered, it just saves as a file and I send it to CRA myself? I'm new to doing returns myself so I don't want to screw up and accidentally send it in.
In the past yeah once you're ready to submit, you hit NETFILE and it generates a .TAX file for you, and you upload that to CRA's website directly.
Some people have said it sends it in automatically for you this year? I dunno because I haven't done mine yet lol.
E: I just checked, and once you hit NETFILE there's the option of sending it to CRA directly or saving the .TAX file only. Might be easier to just use the automatic submission I think.