The first way to add a stage is by simply clicking on the “ADD A STAGE” field, as shown below. After you are done naming the stage, press “Create”.
If this field is not visible to you, scroll to the right.
The second way of adding a stage is by clicking on the plus icon in the top right corner.
After you click on the icon, select “Add stage”.
When you have done this, a sidebar will appear. Here you can name the stage and select to which board it relates to. This way you can add a stage to a board, without accessing it.
After you have completed all of this, you can create your stage by pressing either “Create” or “Create and Open”. If you select “Create and Open” you will be sent directly to the project where your stage is, no matter which project or task you were currently viewing.