How to setup certificate for localhost IIS Express

 Step 1: Clean up all localhost certificates

• Open "Manage user certificates" in the windows search box.
• Select all localhost certificates in the "Personal/Certificates" folder and delete them.
• Select all localhost certificates in the "Trusted Root Certification Authorities/Certificates" folder and delete them. 
• Open "Manage computer certificates" in the windows search box and then do the same things.

Step 2: Using the command line to re-run the setup of the SSL certificate.

• Run cmd as administrator. Navigate to the IIS Express installation directory, the default path is typically:

        cd "C:\Program Files (x86)\IIS Express"

• Now execute the following command to re-run the setup for the SSL certificates. Make sure to update the port number to match yours

IisExpressAdminCmd.exe setupsslUrl -url:https://localhost:44321/ -UseSelfSigned

• You will see the following output: 

Step 3: Re-run your application using IIS Express.

• Restart Visual Studio and open your application.
• Select IIS Express in Debug/Run Configurations and start the application.
• You will see a popup, please select "Yes" to trust the new self-signed SSL certificate you generated for the localhost app. 
• Then a security warning of "Install Certificate" on the local computer will pop up, please select "Yes" to install the certificate. 
• Copy localhost certificate from Personal to Trusted Root Certification Certificates
• After installing the certificate, the application will start normally.

Note: After doing above steps, close the browser then reopen it.

Source: https://learn.microsoft.com/en-us/answers/questions/1330161/iis-express-ssl-certificate-bindings-are-empty