Combining what I have done in the past, if you know your PDF password, open your computer, and visit some online websites in your browser, you can remove the password from the PDF, but you need to enter the password before doing that.
Like:
https://www.sodapdf.com/unlock-pdf/

If you want to remove an unknown password from the PDF, it seems that you need the help of professional PDF password remover software. They are mainly used to work for users who forget the password and want to open the PDF.
Like John the Ripper, Hashcat, and others.
https://www.techspot.com/downloads/6970-john-the-ripper.html
https://www.bestpdfpasswordremover.com/how-to-remove-password-from-pdf.html

Opening or accessing encrypted PDF files is a pretty challenging task. You have to be very careful while removing the password from a PDF file otherwise your data will be lost. I also face many issues while removing restrictions from PDF file, then one my friend suggest a PDF restriction remover tool, and my problem gets resolved. More info:- https://bit.ly/removePDFpassword

How to remove pdf file password

I need help open this it is password locked and I don't know my password

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Chirunomul

I have forgotten my password to open 🔓 my PDF FILES 📁 AS I FORGOT MY PASSWORD please let me know if anyone can help how to generate a new password plz.....

I could not open 🔓 my PDF FILES 📁 AS I FORGOT MY PASSWORD please let me know if anyone can how to generate a new password plz....

Unable to open password protected axisbank account statement pdf. even with correct password

I have password protected documents for Acrobat DC. I purchased the Acrobat DC for 24.99 and still cannot open my documents.

Thank you for contacting us.

To have password protected PDF, you need to have Acrobat Desktop version to add or remove password from a PDF.

Best Regards.

Can’t open pdf document as require password and mine not working

Need a password to unlock , all of mine won’t work