fetch('/api/transactions/create', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json',
    'X-API-Key': 'pk_sua_chave_aqui'
  },
  body: JSON.stringify({
    amount: 99.90,
    payment_method: 'pix',
    customer: {
      name: 'Cliente Teste',
      email: 'cliente@teste.com'
    }
  })
})