When I go to the grocery store i take my backpack cooler, my kryptonite lock, a small tool pouch, and reusable grocery/produce bags.

All my groceries go into this cooler backpack. I also keep reusable produce bags, and grocery bags in it. On the way to the store putting my lock in the backpack works, but on the way home it does not, because it is full of groceries.
I also have a small tool pouch with a handful of hex wrenches. It is fine to go into the backpack.
I also volunteer at a food bank. When I go there i also bring my charger because I get 3 hours of free charging.
This all starts to take up a lot of space in my backpack, so i have been carrying a sling bag, i have to wear it on my chest. Today it was really getting in the way of things.
I am looking for something to carry my lock, and my charger while wearing my backpack.
Update to ad my scooter models
Current, InMotion S1F, my wife it’s taking it when the new one arrives):

New, InMotion RS Jet, as soon as it arrives, it is currently lost in the Fedex Network:


I use a sling bag on my chest now, it has started to interfere with my handlebars, which has led me to an alternative. I used to wear the sling bag on my back under the backpack, but that has become growingly uncomfortable.
I have thought about a hip bag but have not found any so far that look like they would work.
Currently I am using an InMotion S1F, but it is getting replaced by the RS Jet as soon as it arrives, it is currently lost in the FedEx network.
I would love to figure out some on board cargo solutions, i am likely going to be working delivering for domino’s soon and would rather not use my Tacoma for delivering.
Current (my wife it’s taking it when the new one arrives):
New as soon as it arrives:
Check out Osprey: Their packs in general are 10/10 and they offer hip packs that include hydration.
For chest rigs, Hill People Gear is what I use, but there’s quite a few nice options out there.
You could look at storing some stuff on the stem/bars, but I’d recommend keeping that more to lightweight stuff as it can affect handling.
My sling bag is the Osprey Daylite Sling, and I have over of their backpacks. Love their stuff.
I’ve had their Aether for years (backpacking) and it’s been absolutely top notch.