I'm in the Discord attached to the Reddit (mostly ignore it because of the anti-journaling bias), and there's a constant influx of newbies asking "what do I do? How do I play a game ALONE?" The general answer is "Any way you like! Do whatever you want!" Which is true but not helpful.
And it's obvious what they mean is, "I don't have a GM or a group and this seems to say there are games that will provide that experience without the people." And it won't. It provides a different experience, and some players decide they like that or even prefer it.
I sometimes try to nudge them about "what do you like in group RPGs, so we can try to find solo games to suggest?" It's always really hard to get past the "I'm trying out a new type of game and want to know what the rules are." It's like. "What are the rules for taking a walk?" Are you trying to enjoy the scenery, get exercise for your health, get to a destination, just get out of the house for a bit?