Hi @Maurice Stassen,
As Alexey mentioned, you created a next-gen project and this type of project was created to be more simple, with fewer functionalities.
It's not possible to edit the workflow, but if you need more statuses you can click on the "+".
All new status added before "To Do" will be of the category "To do". Status added between "To do" and "Done" will be set as "In progress". Status added after "Done" will be of the category "Done".
If you need to use screens and edit workflow, I believe that the best option is to create a Classic project.
Please, check our article below to find more information about next-gen project and the difference between next-gen and classic:
If you have any other question, please let us know.