Login to the app
On the top right corner, navigate to the Projects.
Here you can see the list of the projects you already have and also add a new one (this is based also on the plan you have, if you are on free plan there you can add only one project)
You can add a project by clicking to Create Project button, put the name of the project at the popup and then click on Create button. After that you can find your added project to the list.