I want the validation process to run when the bool variable I send with emit is false, how can I do this?

My isPhoneValid variable is where I hold the boolean value.

 const schema = Yup.object().shape({
      isPhoneValid2:isPhoneValid.value, 
      phoneValid2:Yup.string() .when(isPhoneValid.value , { 
        is: true,
        then: Yup.string().required()
      })
})