Conditions in submitButtonText option

How I can set condition on **settings.submitButtonText** property? I wanna to set Submit button text depending on object variable **questions[0].value**. 

`export const field = {
  settings: {
    submitButtonText: function() {
      return this.questions[0].value ? 'Edit' : 'Send'
    }
  },
  questions: [
    {
      type: 'text',
      key: 'field',
      value: ''
    }
  ]
};`