If you are planning to use your own SSL certificate and using Sitecore 9.3 installation wizard then you must make sure that your SSL certificate is exportable when you install SSL on your server.
Check the box so your SSL Certificate is Exportable for Sitecore 9.3 Installation |
Once you make it exportable then the Sitecore 9.3 installation wizard will be able to export the certificate and continue with the installation or else you will get the following error message.
[ IdentityServerCertificates_CreateS... : NewSignedCertificate ----------------]
Cannot export non-exportable private key.
[TIME] 00:00:11
Cannot export non-exportable private key.