fetch post

main.js

function getDataFromApi (summ) {
  return new Promise((resolve, reject) => {
    /* global fetch */
    fetch('https://gehaltsrechner.bonushammer.com/gettax', {
      method: 'POST',
      headers: new Headers({'Content-Type': 'application/json'}),
      body: JSON.stringify({summ})
    })
      .then(blob => blob.json())
      .then(data => resolve(data))
      .catch(err => reject(err))
  })
}