Would the ADA require accomodations be made for someone who was unable to patronize the business bc of their disabilities?

I'm not sure how to phrase it succinctly, so my title might be misleading.

I ran across a woman sharing her experience at a restaurant where she was denied bringing in outside food despite having severe allergies that prevented her from eating the food or drinks in the restaurant. She couldn't even have the water. She was told outside food was not allowed due to health concerns and accepted that answer, but then in retrospect felt they violated her rights.

I'm curious if they did. If a restaurants purpose is to sell food and drinks, which she wasn't interested in, and she had full access to seating and bathrooms and stuff, would they be required to also allow her to bring in outside food and drinks?

I think maybe that accomodations would make more sense to me if she were eating the food, for example, but needed to bring in her own water. Or if she were patronizing a business where food was a secondary offering, like maybe a movie theater or hotel. Like if she were there to partake in a service they offered, they would be required to allow her to partake in that service.

But if she's not, how does it work? They weren't saying she had to leave or anything. Just that she couldn't eat outside food on the premises.