Actually now that I went in the course to check those options, it turns out I don't see them! I have everything in the screenshots on that guide except those first 2 options for joining with a code
@ek , I just checked and this option is available in my Free for Teachers (FFT) Canvas course, but not for my Institutional Canvas course. I checked and it appears that this is because on the Canvas admin settings side of things my Institutional instance of Canvas does not have the "Self Registration" box checked. If you're a Canvas Admin then you'd need to check this box in order to enable this feature - What is the difference between self-enrollment, self registration, and open registration? If you're not a Canvas Admin then you'd need to contact your Canvas Admins too see what can be worked out.
Hope this helps!