Grocery store havoc

i know this has to be so fustrating for you, my son who is now 3 used to be the same exact way which made me completely avoid taking him out. Have you tried giving her any toys or your phone ? Just something to maybe distract her

This may not be good advice but its what we did.

Talking to them about why we need to go to the store and why they need to behave.

If a kid can behave long enough to get what you need, they get something they want (a snack we were going to get anyway, a candy from checkout, sometimes a small toy if theyve been good that week.)

Letting them help do the shopping. If they write they can make the list or can draw what we need. Ask what kind of butter do we use? Do you know where it is?

If push comes to shove, they have to put their hand on the cart. If their hand leaves the cart, we leave the store. No fighting, yelling, nothing, we just walked out, and sit in the car. If they're willing to go back in, we do. If not, we go home.

Headphones if they're easily over stimulated by noise.

Tablet or phone if you need to.

Sometimes ive had to break down and hold their hand and let them scream it out while i get what we need when ive been desperate.

Does your grocery store offer pickup so you don’t have to get her out of the car?

I made a similar post before and someone gave me an idea. They said that they print grocery items as pictures, and they let their child help look for the items.
Not sure if this would distract her, but maybe you could laminate it and give her a dry erase marker.