IP:4357 in accessible but IP:8123 no (1st installation)

in the :4357 page I have this:
“”# Home Assistant observer

Supervisor: Connected
Supported: Supported
Healthy: Healthy"

but to tha :8123 pagne i have “ERR_CONNECTION_REFUSED”

If I can share some logs or info to help ask me what do you need.

excuse, the English language is not my language.

Already discussed here:

Installation issues - Installation / Home Assistant OS - Home Assistant Community