I applied for my own mobile phone certificate. I downloaded it. I don't know how to do it after that. I downloaded the certificate to sign the font.
If you have a computer, right-click the certificate, select Import Certificate, and a command box will appear. Just press Enter to put the downloaded software to be signed into a folder, open a signing tool (the DOSPY signing tool v2.2. 10.0322.exe can be downloaded at the certificate point), and then find the software to be signed. Right-click to choose to sign this file or sign all files, and the signed software will appear in the same root directory. It is the contracted software, hehe.