Workers are your main helpers in the game, performing tasks related to resource production and collection.
How to assign a worker to a task:
Click on the character (this will act as the "Add Worker" button).
If you have a free worker, they will immediately start the job.

If the game reports that a worker is unavailable when you try to assign them, this is not an error!
What does the "Worker unavailable" status mean? ❌
This means that your worker is currently busy—they are already performing a task at another facility or production building.
Solution: Simply wait until the worker finishes their current task at the other building.