We recently had a request for disabling the Sitecore Identity Server so that we could save an outbound call in Azure Infra by requesting the Sitecore login within the website.
The good news is that this option is Out-of-the-box provided by Sitecore, there are no code changes required.
We need to move the “Sitecore.Owin.Authentication.IdentityServer.Disabler.config.example” file from \App_Config\Include\Examples to \App_Config\Include\Environment
Rename the file to “Sitecore.Owin.Authentication.IdentityServer.Disabler.config” (remove the example extension), and we are done.
Once the above configurations are done, recycle the app-pool and try to login to Sitecore.
Hope it helps!
Thank you.. Keep Learning.. Keep Sitecoring.. đŸ™‚