Adoption of new constitution by chad may 2018
I think there may be a mistake here.
After conducting a thorough search, I couldn't find any evidence of Chad adopting a new constitution in May 2018 or any other time. Chad has had several constitutions since its independence in 1960, but I couldn't find any information on a recent adoption of a new constitution.
If you have any more information or context about this, I'd be happy to help clarify.