Update
The following appears to work now using Poetry version 1.2.0b3 on macOS version 12.5.1 (Intel):
poetry source add prodigy "https://download.prodi.gy"
poetry config http-basic.prodigy <personal license> ""
poetry add --source=prodigy prodigy
We haven't tested for different OS/Poetry versions but want to post in case it may help others.