Cannot install pgadmin4-apache2

Hello,

I am unable to install pgadmin4-apache2 on a new server running Ubuntu
18.04 server. I am following the instructions on
https://wiki.postgresql.org/wiki/Apt, but "sudo apt install
pgadmin4-apache2" returns the following:

Some packages could not be installed. This may mean that you have
> requested an impossible situation or if you are using the unstable
> distribution that some required packages have not yet been created
> or been moved out of Incoming.
> The following information may help to resolve the situation:
> The following packages have unmet dependencies:
> pgadmin4-apache2 : Depends: pgadmin4-common (= 4.16-1.pgdg18.04+1) but it
> is not going to be installed
> E: Unable to correct problems, you have held broken packages.

and "sudo apt install pgadmin4-common" returns the following:

Some packages could not be installed. This may mean that you have
> requested an impossible situation or if you are using the unstable
> distribution that some required packages have not yet been created
> or been moved out of Incoming.
> The following information may help to resolve the situation:
> The following packages have unmet dependencies:
> pgadmin4-common : Depends: python3-werkzeug (>= 0.15) but 0.14.1+dfsg1-1
> is to be installed
> Recommends: pgadmin4-doc but it is not going to be
> installed
> Recommends: python3-psycopg2 (>= 2.8) but 2.7.4-1 is to
> be installed
> E: Unable to correct problems, you have held broken packages.

I'm not sure how to proceed. Any help will be appreciated.

Thanks,
Gabriel