Signing Nvidia Drivers

Hi all,
I’m working on a Kubernetes single-node cluster based on Ubuntu23 with RKE2 and I want to use Nvidia drivers signed based on the GPU-Operator helm chart.
The current driver that we are using is 535.129.03
In the past with ubuntu22 we were using this image:

nvcr.io/nvidia/driver:535.129.03-ubuntu22.04

Now, for ubuntu23 we are able to compile the drivers on the fly and signing the Nvidia kernel module like this:

sh NVIDIA-Linux-x86_64-535.129.03.run -x \
--module-signing-secret-key=/path/to/signing.key \
--module-signing-public-key=/path/to/signing.x509

based on this:
https://download.nvidia.com/XFree86/Linux-x86/361.45.11/README/installdriver.html#modulesigning

but, with the _create_driver_package() function we have issues to sign the driver kernel modules using the ‘donkey’ tool:

This is the snippet from the source code:

if [ -n "${PRIVATE_KEY}" ]; then
  echo "Signing NVIDIA driver kernel modules..."
  donkey get "${PRIVATE_KEY}" sh -c "PATH=${PATH}:/usr/src/linux-headers-${KERNEL_VERSION}/scripts && \
    sign-file sha512 \$DONKEY_FILE pubkey.x509 nvidia.ko nvidia.ko.sign && \
    sign-file sha512 \$DONKEY_FILE pubkey.x509 nvidia-modeset.ko nvidia-modeset.ko.sign && \
    sign-file sha512 \$DONKEY_FILE pubkey.x509 nvidia-uvm.ko"
  nvidia_sign_args="--linked-module nvidia.ko --signed-module nvidia.ko.sign"
  nvidia_modeset_sign_args="--linked-module nvidia-modeset.ko --signed-module nvidia-modeset.ko.sign"
  nvidia_uvm_sign_args="--signed"
fi

All the time the process stop here saying:

"donkey: could not establish connection: Connection refused"

at the end of the nvidia driver dockerfile the entrypoint is this:
ENTRYPOINT ["/usr/local/bin/nvidia-driver", "init"]

I really appreciate if any of you can help me to solve this issue or if you can give me an advice about how to solve it.
Thanks in advance!

Have a nice week,
Antonio.