Wrong secret when working with the Cryptonator API?

Question

RESTful API

Hello, I work with the cryptonator
API. I wrote this piece of code

let path = `/balance`

    let value = Number(1)
    let currency = 'bitcoin'
    let language = 'ru'
    let item_name = 'new'


      let url = `${config.payment.url}createinvoice`

      let string = `${config.payment.id}&${item_name}&${currency}&${value}&${currency}&${language}&${config.payment.secret}`

      let secret_hash = crypto.createHash('sha1').update(string).digest('hex')

      let form = {
        merchant_id: config.payment.id,
        item_name: item_name,
        checkout_currency: currency,
        invoice_amount: value,
        invoice_currency: currency,
        language: language,
        secret_hash: secret_hash
      }

      console.log(form)

      let headers = {
        'content-type' : 'application/x-www-form-urlencoded',
        'charset': 'utf-8'
      }

      request.post({
        headers: headers,
        url: url, 
        form: form
      }, function(err, response, body) {

        console.log("Get response: " + response.statusCode)
        console.log(body)
      })

And when checking, the error {"error":"Invalid Secret hash"} constantly crashes, maybe someone worked and knows what the problem is?