Chev's post in American Truck Simulator Version Has Updated; TruckersMP Should Issue An Update When Possible was marked as the answer
An update will be ready as soon as possible and will be posted under development announcements.
Also, there are a few topics going over how to upgrade and downgrade your current game version.
Have a great day or night!
Chev's post in TruckesMP on Mac was marked as the answer
Currently, the mac version is unsupported and will remain unsupported until the development team decides on making it supported.
There's multiple threads that go over this certain topic.
Also, please use the search bar if you would like to know more information regarding the supporting of the mac version.