How could I sign a file with a cer file

Question

Hello, I've been using .pfx files to sign my files. My certificate expired last year so I bought a new one from the vendor. They told me that As of June 1, 2023, you will no longer be able to issue your standard OV Code Signing certificates. The process of requesting code signing certificate has been changed. CS certificate are no longer allowed to be stored in PFX format. and give me this link https://www.entrust.com/blog/2022/09/ca-browser-forum-updates-requirements-for-code-signing-certificate-private-keys/. So now I only have a cer file and it can't export a pfx file. How could I sign a file with a cer file?

Answer 1

https://www.sectigo.com/faqs/detail/Code-Signing-with-an-OV-or-an-EV-Code-Signing-Certificate/kA03l000000c4TX