how can I make readthedocs find my configuration file which is already in GitHub project repository root directory?

I am trying to publish a Python package's documentation on readthedocs.org.

It was being published in previous releases. However, I am getting

"The configuration file required to build documentation is missing from your project."

Despite my .readthedocs.yaml being here: project Github repository

How can I fix this? I tried pointing to the root directory of the project from the advanced settings on readthedocs, but nothing seems to help.

Thank you.

From your https://github.com/icebearcanada/cavsiopy/blob/14d80b525657f3b219cf4b8217e76ea99f45d828/.readthedocs.yaml#L1-L6

# Read the Docs configuration file for Sphinx projects
# See https://docs.readthedocs.io/en/stable/config-file/v2.html for details

# Required
versions:
  - master

The helpful link leads to documentation for the accepted keys. You need to change this:

# Required
version: 2

versions is not a valid key. Furthermore, you do not need to specify a branch such as master because this configuration file is on a branch.