How to create a yup schema for a nested dictionary

I am trying to create a yup schema from an object that has a nested dictionary. We are using typescript.

export interface MyExampleInterface {
    name: string;
    organization: string;
    nestedDictionary: { [key: string]: string[]; };
    isValid: boolean;
}

The nestedDictionary part is the one I am really struggling with. There are not many solutions online, and none of the ones available seem to use typescript.