Flask error when Exporting Servers

[Greg Diersing]

Hello,

I’m running a pgAdmin4 container in AWS ECS Fargate.  When attempting to export 
servers (to automate future upgrades) I’m getting a Flask error.  Is this a 
problem with my syntax or my container configuration?  

/pgadmin4 # python3 setup.py <http://setup.py/> --dump-servers servers.json
Traceback (most recent call last):
  File "/pgadmin4/setup.py", line 33, in <module>
    from pgadmin.model import db, User, Version, ServerGroup, Server, \
  File "/pgadmin4/pgadmin/__init__.py", line 23, in <module>
    from flask import Flask, abort, request, current_app, session, url_for
ModuleNotFoundError: No module named 'flask'

Thank you,
Greg