Set up Discourse for development on Fedora Linux

I am stuck after installation today on Fedora 41 with the following issue when I connect to localhost:3000 and click on register :
“no administrator emails were defined during setup”; the message provides how to add an administrator email.

I’ve failed to successfuly add an admin acount following this procedure because of 2 errors when using ./launcher enter app :
1° First solved error was: no app.yml file is present → I copied the sampleapp.yml from the sample folder to the container folder, then modified to add email adresses, then did the rebuild with /var/discourse/launcher rebuild app
2° Second error is not solved :
Error response from daemon: No such container: app
If I use the rake commands to create an admin it tells me no rakefile found

Can anyone please help?