You can only create a login for an origin (protocol and hostname) like "https://bcbsfepvision''.''com", so it isn't possible to create the login for "https://bcbsfepvision''.''com/portal/" This doesn't look like a problem with that origin since the Inspector shows that the website uses an unusual configuration to code their login form. Firstly, the form is in an iframe (https://idoc.bcbsfepvision.com) *https://idoc.bcbsfepvision.com/members/FEP/Authentication/Login Secondly, both username and password fields are of type="text" and that makes it impossible for Firefox to detect this as a login form even if I use "This Frame -> Open Frame in New Tab". This configuration would require a special recipe to make this work with the Firefox Password Manager. *https://developer.mozilla.org/en-US/docs/Tools/Page_Inspector/How_to/Examine_and_edit_HTML