About two years ago I created an odt file in LibreOffice and saved it with a password.
I can’t remember the password now. Is there anything I can do?
“Today I managed to get hold of another person’t password-protected document, and I don’t know the password. Is there something I can do?”
This question is technically equivalent to yours. So, if your (legitimate) case could be solved, then my depicted one would also be “solved” in the same way.
This question comes up from time to time. There were some helpful replies in this earlier Q&A. Good luck.