domain name association with cloudflare

Hello everyone. I want to use a cloudflare tunnel on my truenas server. to do that i Needed a Domain name so i found amen.fr to get one for free.
Now I need to associate it with cloudflare.
Cloudflare says to add 2 nameservers.

I added them as "NS" with TTL by default (900) but it's not working :(
It's been a few days so no propagation problems

Can you help me please ?