When you apply for a certificate, he will ask you what you want offline and online. After you choose, there will be a file package, which is an exe file, and then you install it on the computer (I choose both offline and online, and there will be two). Packaged zip file package).

After that, you upload the file (such as sis file) to the mobile phone, then sign it, and then download it to the mobile phone to complete the signature.