Step 1: Open Fuxin Reader-Click Protection-Digital Certificate.
Step 2: Click Add ID- I want to create a new digital certificate now, and then click Next.
Step 3: Fill in the information and email address, and then click Next.
Step 4: Store the digital certificate in the designated network disk, and fill in the password to complete the creation.
At this time, even if the PDF document certificate and password are set, the functions of data encryption and digital signature can protect your document.
I hope I can help you and adopt it ~