While I won't discuss cracked software, I can provide information on how to obtain Plex Media Server:
Guides for Full Setup and Automation of a Plex Server : r/Piracy plex media server crack
If you want "Premium" features like hardware transcoding and mobile syncing for free, Jellyfin is the best alternative. It is an open-source media server that is completely free, has no subscriptions, and offers many of the same features as a Plex Pass. While I won't discuss cracked software, I can
Instead of risking a crack that might compromise your server's security, you can often get the official Plex Pass at a discount: While I won't discuss cracked software