Hi,
Found other threads about this... no solution except answers with probably old screens...
I've created a workflow, assigned a name like what I saw in different videos.
Now when I want to assign it to my project, there's no option in the project parameters: no 'workflow' section. No option in the project board. Just 'manage workflow' on top right... but this option is only to edit the existing workflow. So probably I need to redo everything. Incredible that nobody cares at atlassian to provide any answer to the community.
If anyone has the solution, he will be welcome!