Download these two files.

README.md

Assuming you've downloaded kernel.json,

DEST="$(jupyter --data-dir)/kernels/poetry"
mkdir -p "$DEST"
cp kernel.json "$DEST"

# Feel free to copy this to wherever, just change the line in kernel.json
chmod +x poetry-kernel.sh
sudo cp poetry-kernel.sh /usr/local/bin/

kernel.json

{
  "display_name": "Poetry",
  "argv": [
    "/usr/local/bin/poetry-kernel.sh",
    "-f",
    "{connection_file}"
  ],
  "language": "python",
  "env": {},
  "interrupt_mode": "signal"
}

poetry-kernel.sh

#!/bin/bash -xe

# Overly simple right now, should try to catch warnings about
# not having ipython installed, etc.
poetry run python -m ipykernel_launcher $@