Locked out - no access to UI

I played arround with Duckdns and extarnal Access. It looks like that i have made a mistake in the network names … After a reboot I cant access the UI. No messages in the console.
no Accsess via internal IP:8123 or https://homeassistant.local:8123
thx for help !

Do you have SSH access?

I have a Rasp4 and I can connect a keybord and monitor to it. Meanwhile I can access with https://internalip:8123

 base_url: https://myname.duckdns.org:8123
    ssl_certificate: //ssl/fullchain.pem
    ssl_key: /ssl/privkey.pem
    ip_ban_enabled: true
    login_attempts_threshold: 3

this is what I have in the config. that works for a while

There have been problems with duckdns.org in the last 48 hours. But seem to have resolved now.
See this thread No longer a stable connection via duckdns domain

Try again, hope it’s working. At least you got the local access working. My local access was working throughout.