I use to be the instructor for that NMI course for 11+ plus years. it was approved as Flyer69 reported, you can find the course approval letters on NMC website for each course, which clearly will tell you what the course is approved for.
I for one, DO NOT recommend Cel Nav to be taken ONLINE. As so clearly stated by others, have an instructor on hand as you go through the material is key. Basically the course JAMS, 2 semester worth of Academy material and over 16 cel nav problems into 80 hours/2 weeks. It’s just NOT the way to learn Cel Nav. if you have never done it before.
I highly advise getting tutored or take it at a school over a period of time. If you really want the art of Cel Nav and learn it as a profession, it takes time simple as that. If you just want to pass the test, well that’s a different Course to steer for sure.