I am unable to Open the app

[Caleb Akintayo]

       Good day, Sir/Ma, my name is Ayowale, a Nigerian.
I recently downloaded PostgreSQL and installed it successfully. But I am
unable to open "pgadmin 4" It is showing a fatal error and bringing a
configuration page, but whenever I try to configure it brings a different
port number from what I have initially entered.
      Please I am counting on you for a suggestion on how to go about it.
Thanks.