occ upgrade won’t download or install any updates nor will it check for new updates. Please read the documentation how to proceed:
Depending on your initial installation way choose the instructions there and proceed with the update to 9.0.4.
I’m closing here for now for the reasons explained in Why should i create a new thread for each question / problem?. If you need further help with the update please create a new thread in the help category for oC 9.0.x