Cant Play Media With Mi smart Speaker ( By google cast)

Hi. I’m trying to play an mp3 file by my Mi smart speaker with google cast.
so I’ve written an automation and it was working. But now I have installed DuckDns for accessing HA from outside. But this automation stopped working. I’ve tried resetting the Speaker but that doesn’t work.

I forgot to say
also TTs doesnt work

Hi, have you solved this issue? I have exactly the same problem