Validating object unknown properties

[Yonier]

I have a javascript function where it push new properties inside a object, but this name properties are not always defined, so i want to add rules to those object properties, i have a code like this:

`
const validationSchema = object().shape({

        box: object() // i want to add string().required() to all the new properties of that object...
    })`

is this possible?, thanks.

yup version:
"yup": "^0.32.9"