Your question is a little vague, but if I were to guess, I would say the only place you would need login credentials when running a scan from an IDE plugin is if you want to upload the scan results to SSC. So the login credentials in this case would be your SSC username/password or a ToolsConnectToken from SSC.
Why don't you disclosure intellij remedation plugin download link? ?My plugin is too old to compatible with new intellij idea, and I don't want to ask to the man who have fortify official website account in my company for just this little thing.
Are you referring to the Fortify on Demand plugin? If so, it can be found on the JetBrain Marketplace here plugins.jetbrains.com/plugin/9943-fortify-on-demand