Why username &#x2F; password? On mobile this is a dead approach. See <a href="https:&#x2F;&#x2F;docs.fabric.io&#x2F;android&#x2F;digits&#x2F;digits.html" rel="nofollow">https:&#x2F;&#x2F;docs.fabric.io&#x2F;android&#x2F;digits&#x2F;digits.html</a>