Hope you are doing well. Thanks for writing in about working with protected PDFs.
Removing passwords from a PDF is a workflow that can be done using the desktop version of Acrobat.
We are very limited in our ability to help you with passwords, as we do not store passwords on our servers for any PDFs.
If you do not remember the password to a particular file, the only solution here would be to either create a fresh copy of the file without the password or reach out to the creator of the file.