Authentication Pop up displayed by Chrome is available in Inspect tool but not in PageSource

Hi Team,

I was trying to fill userid and password for an authentication Pop up displayed by Chrome browser
I see that Inspect tool was able to recognize the edit boxes but when I tried find Element using XPath those elements are not available.

Can anyone provide any input about this discrepancy?
Do we have any workaround for this?

Pls find my attached screenshot: