How to Recover PDF Password If You Forgot the Owner Password or User Password
In PDF file, you can set two kinds of password--Owner Password and User Password. The Owner Password can keep others from reading the PDF document, in other words, the one who does not have the owner password even can't open the PDF document. While the user password protect the document from being editing, amending or printing. If you forgot either of the password, you might be frustrated, if you want to need the document urgently. Now no matter what kind of password you forgot, you can use PDF Password to recover the password.
For more details, you can refer to https://www.cocosenor.com/articles/pdf/how-to-unlock-a-pdf-file-when-forgot-pdf-password.html