Does it actually work during preview in AE? If not, then something is wrong. eitehr way, you have not provided proper info about effect settings, render settings, your comp, so nobody can really tell you where the problem could be. Just saying that it doesn't work is never a good way of asking for help.
I watched the first few minutes of the tutorial and found at least three really bad workflows and inefficient techniques so I gave up on the tutorial. It's one of the worst that I have seen even before I got to the part about adding Twitch.
You have to vet your trainers. I'm not surprised that you are having problems following that tutorial.
Generally the way to solve a problem of an effect not working as expected is to pre-compose the layer you are having problems with making sure you move all attributes to the new comp, then you apply the effect that is not working to the nested comp (the layer or layers you just pre-composed).
By the way, the first clue that the person that made the comp was an amateur and was giving bad advice is when they included an annoying music loop. The second clue was when they set a background color for the composition. Set a comp's background color does not change the background color of the rendered movie if it includes transparency, it only effects the way the edges of transparent objects in the comp are calculated with you export with pre-multiplied color. IOW, change the background to white and add some black text, then render with an alpha channel and you'll get some black text on a black background with some very faint gray edges in the curved portions of the text. On some very rare occasions this is helpful to a project. Unless you know exactly what you are doing and have a lot of experience working with alpha channels and video, setting the background color of a composition is almost always a useless exercise. Once the background color was set a whole rigamarole was done to create a vignette that was also a very inefficient way to do this.