My bet is that the Doctor told him that he needs to do something to lose weight and not become bed ridden, so he or she recommended walking. Lou sees a grifting opportunity to buy a new shiny.
It’s a win-win scenario for him. Because if he doesn’t get the donations and can’t buy the AirPods, then he’ll just refuse to walk anyways and see it as a perfectly valid reason that he can’t do the bare minimum of exercise.
If he does get the donations and manages to buy the AirPods, then he has a new shiny to make him feel better about his life for an hour….but he still probably won’t go for a walk, that’s way too

.