Here is the official upgrade documentation

TL;DR

1. Back up anything important
2. Change bookworm to trixie, bookworm-security to trixie-security, and bookworm-updates to trixie-updates in your sources.list
3. sudo apt update
4. sudo apt full-upgrade

Pay attention to your full-upgrade. Good luck.

Can you post the contents of your /etc/apt/sources.list file? Presumably it’s as simple as changing all the bookworm references to trixie.

The trixie freeze has started. I would simply move there.