Hi there!
The English translation of the G1 Licence needs to be reviewed by a native speaker, especially on how the sentences are built.
A topic was open on this a few years ago but I don’t think it has been worked on since.
Here is the link I found on the Git Lab repository for the G1 Licence : g1_monetary_license_en.rst · master · documents / g1_monetary_license · GitLab
Is this the official version?
How can someone contribute to improve it?
Is the licence available on Cesium for people to read it other than when they create a member account?
This is the source repository, yes. Clients and websites are embedding the license files from this repository.
Sure, anybody can ask for a GitLab account, fork the repository and create a merge request.
This is for technical people which know a bit about git and development processes.
For non-technical contributors, I had the project to have the monetary license translatable from Weblate, but I gave up on that in the meantime, to work on other priorities. It turned out to be more complex task than I first thought.
The license is available to read anytime, see SHOW LICENSE button on Cesium