I have tried to get the module to run, but have also failed. It seems to me that there is a problem with gkeepapi. A simple query with gkeepapi already fails.
There seems to be a workaround with docker (see https://github.com/kiwiz/gkeepapi/issues/81), but I didn’t tested that. In the issue discussion the maintainer of gkeepapi mentioned waiting for a new release of gpsoauth. Then MMM-GoogleKeep might work again without any tinkering 🙂