You cannot “just download” MicroStrategy 10.4. You must have a legacy license and either an archived copy or a support account. Contact MicroStrategy Support directly if you legally own a license.

MicroStrategy 10.4 is an archived, unsupported version (released around 2017-2018). MicroStrategy no longer hosts this version on its public website. You cannot download it from the official “Download” section unless you have a legacy Support Account with access to the old archives.