HA on Freebox Ultra. Port access problem

I replaced my Freebox Revolution with a Freebox Ultra in order to install Home Assistant on a VM (the Revolution does not have a VM).
I installed a 1TB NVME SSD on which I placed https://github.com/home-assistant/operating-system/releases/haos_generic-aarch64-12.4.qcow2.xy from which I extracted the image.
The resources allocated to the VM are: 32 GB of disk, 2 GB of RAM (the maximum possible on Ultra!) and 2 CPUs.
The VM starts then home assistant too (after a first forced shutdown) until the homeassistant login: prompt (on the VM console).
I retrieve the LAN IP (
On my browser I type → This site is inaccessible does not allow the connection.
The ping on is ok.
I can connect as root on ha from the console.
I would like to install the ssh add-on but it seems that it is not possible from the console.
On, the messages : Home Assistant observer -Supervisor:|Connected| - |Supported:|Supported| - |Healthy:|Healthy|
I feel like I am going around in circles.
NB: I have never used HA except for a blank home automation installation on a Pi400.
Do you have any idea for this port problem?

Is there a firewall active on the freebox ?

No for IPv4.
Yes for IPv6 but disabled.