Click on environment in the menu in the top right corner to access the environment dialog.
A dialog will open where already a default environment is created. This environment will automatically be created when no other environment exists. Let's create a new environment by clicking on the button in the top left corner.
In the new dialog window enter a unique environment name and confirm the creation.
Close the environemnt window. At the top of the request list you can see name of the default environment. Click on the dropdown and select a environment to change it.