title: Unable to integrate Mpesa Api into my android app
body: <p>I am trying to integrate MPESA API into my android app using the procedures given by Daraja. On launching my application, the following error is displayed in my Logcat</p>
  
  <pre><code>D/OkHttp: {
                      "requestId": "16583-1090909-1",
                      "errorCode": "400.008.02",
  </code></pre>
  
  <p>D/OkHttp:                     "errorMessage": "Invalid grant type passed"
                      }</p>
  
  <p>and after entering a Phone number and amount to be sent, the Sim Toolkit is not being brought to the front.
  The following error is displayed in my Logcat</p>
  
  <pre><code>D/OkHttp: {
                      "requestId":"29178-5342114-1",
  </code></pre>
  
  <p>D/OkHttp:                "errorCode": "404.001.04",
                          "errorMessage": "Invalid Authentication Header"
                      }</p>
  
  <p>This was my expectation: On pressing the "Pay" button, I should be prompted to the sim toolkit requesting for my Mpesa pin to continue with the payment.</p>
  
  <p>I will appreciate any assistance that will be offered.</p>