stripeTestCypress.js

 const fillInStripeForm = () => {
    const input = [
      ['cardnumber', '4242424242424242'],
      ['exp-date', '1220'],
      ['cvc', '123'],
    ]
    cy.wait(1000)
    cy.get('.__PrivateStripeElement > iframe').each(($element, index, list) => {
      cy.get($element).then(($iframe) => {
        const body = $iframe.contents().find('body')
        cy.wrap(body)
          .find(`input[name=${input[index][0]}]`)
          .type(input[index][1], { delay: 10 })
      })
    })