These packages are build for myself and a few friends and are completely unsupported by the Debian Maintainers!
Install if you like but don't blame me if your computer explodes ;-)
But at least these are only simple backports so there shouldn't arise any problems. Of course if there are any dependency problems or other kinds of backporting related bugs I will try to figure them out, just send me an email :)

Simply add the following to your sources.list:

deb https://slashproc.org/debian/dists/trixie/ ./

Or if you prefer a modernized DEB822 repo file in /etc/apt/sources.list.d/ folder:

sudo wget -O /etc/apt/sources.list.d/slashproc.sources https://slashproc.org/debian/dists/trixie/slashproc.sources

If you only want to install an explicit package from the repo you could use a not modernized DEB822 format:

deb [arch=amd64 signed-by=/usr/share/keyrings/slashproc.gpg] https://slashproc.org/debian/dists/trixie/swtpm/binary-amd64 ./

Now add the gpg-key:

sudo wget -O /usr/share/keyrings/slashproc.gpg https://slashproc.org/debian/slashproc-debian.gpg

After executing 'sudo apt update' you will hopefully be able to install packages from the repository without any warnings from apt.
E.g. by executing 'apt-get install -t trixie-backports swtpm-tools'

The Sources are also available in the repository (but not viewable via web):

deb-src https://slashproc.org/debian/dists/trixie/swtpm/sources ./

If you want the deb-src for the complete repo use:

deb-src https://slashproc.org/debian/dists/trixie ./

Or if you prefer a modernized source in the /etc/apt/sources.list.d/ folder:

sudo wget -O /etc/apt/sources.list.d/slashproc_src.sources https://slashproc.org/debian/dists/trixie/slashproc_src.sources

Current packages:
swtpm