This is what I get:

  20 0 obj
  <<
      /R 4
      /O (...)
      /U (...)
      /P -1548
      /Length 128
      /V 4
      /EncryptMetadata true
      /Filter /Standard
      /StmF /StdCF
      /StrF /StdCF
      /CF <<
      /StdCF <<
      /AuthEvent /DocOpen
      /CFM /AESV2
  >>>>>>
  endobj

I tried a bunch of tools, including https://www.elcomsoft.com/apdfpr.html?src=prog_apdfprp to get it to quickly remove the password, but nothing worked :/