pgAdmin 4 in web mode on an Ubuntu 20.04 (Focal) system.

I am currently facing an issue while installing pgAdmin 4 in web mode on an Ubuntu 20.04 (Focal) system.

Error: 

/usr/pgadmin4/venv/bin/python3: can't open file '/usr/pgadmin4/web/setup.py': [Errno 2] No such file or directory

ls -l /usr/pgadmin4
total 24
drwxr-xr-x 4 root root  4096 May 15 09:01 bin
-rw-r--r-- 1 root root 11206 Apr  2 10:26 sbom-desktop.json
-rw-r--r-- 1 root root   474 Apr  2 10:26 sbom-web.json
drwxr-xr-x 6 root root  4096 May 15 08:58 venv

Since the pgAdmin installation did not automatically create the required virtual environment, I manually set it up using python3.8 -m venv /usr/pgadmin4/venv, but the setup still fails due to a missing setup.py file in /usr/pgadmin4/web/

sudo python3.8 -m venv /usr/pgadmin4/venv
source /usr/pgadmin4/venv/bin/activate

I followed the following steps from 

Please advise.

Thanks,