The 'Inspect" option is missing from the the pop up (right-click menu) on the credential fields in the Spectrum WEB GUI login (http://<ONECLICK_HOST>:443/spectrum/index.jsp) page:
DX NetOps Spectrum Release : 10.4.x
Component : OneClick
The Inspect option is browser based and it appears in 21.2.x since it is restructured in the latest Spectrum releases.
The 10.4.x version uses the old design and it will not show up on right click.
If you upgrade to 21.2.x (or later), then the 'Inspect' option will appear automatically when you right-click on the login fields of the authentication dialog.
However, you should still be able to achieve the Inspect option by pressing F12 button (Developer Tools) and it shows the same pages Inspectdoes.
If this is not an acceptable solution, then the only option is to upgrade to 21.2.x (latest version is 21.2.10).