Record popup in Chrome browser

Hi, we are using Silk Test Classic 21.0. We are trying to record a flow in our application using Silk Test Classic with Chrome browser.  There is a dialog popup like below, and the Silk is not able to recognize it and we are not able to record it.  

Anyone has any idea about how we can record it.  We want to enter the Username and password and then click the sign in button.

Thank you!