Yes, in the 70's I could buy darkroom supplies at a large supermarket (department store like), but then still one would at least had to buy an expensive filter-coated bulb and screw it into the socket of the bathroom luminaire, if such was possible.
Maybe the idea was to process the paper directly under the enlarger. Illuminated by that tiny lamp. But I do not see any kind of red filter in the listing.
EDIT:
At that site underneath the comment is a listing of the stuff to acquire seperately. As a torch light with red or green transparency paper in front of it.
Clumsy, but it would have added to the adventurous mood of that, a kind of conspirative work.