Backpack harness leash

So my son has been walking since 9 months and likes to walk on his own when we go to stores and such. And I just don’t wanna put him down and have him walk off obviously, so which child harness leash would you all recommended if purchasing in the future or if y’all already have one?? I don’t like the wrist ones because then you’re just tugging they’re arm around when reaching. Preferably backpacks!