I have a digital signature that appears in File => Info => Protect Workbook => Add a digital Signature
However, it does not appear in VBA Editor list: Tools => Digital Signatures => Choose. In VBA it only list my self-created digital signature.
How do I add the real digital signature to my VBA project? I enabled all purpose for the real one. It's visible on Personal tab in Internet options and is valid.
The certificate needs to be a certificate that was issued for code signing. Certificates that were issued for other purposes will not appear there. So check the purpose of your certificate.
Therefore you can run certmgr.msc
(using Win+R) find your certificate, right click on it -› properties and check which purposes are set in the first tab there. If it does not mention code signing there, you cannot use that certificate.