ImportError: No module named 'passlib.totp'

I have problem when I try to install pgAdmin4 on ubuntu 16 :( and pip install passlib don't help me. Somebody knows how to fix it?

    from pgadmin.model import db, User, Version, ServerGroup, Server, \
  File "/usr/share/pgadmin4/web/pgadmin/__init__.py", line 25, in <module>
    from flask_security import Security, SQLAlchemyUserDatastore, current_user
  File "/usr/lib/python3/dist-packages/flask_security/__init__.py", line 16, in <module>
    from .core import Security, RoleMixin, UserMixin, AnonymousUser, current_user
  File "/usr/lib/python3/dist-packages/flask_security/core.py", line 60, in <module>
    from .totp import Totp
  File "/usr/lib/python3/dist-packages/flask_security/totp.py", line 12, in <module>
    from passlib.totp import TOTP, TokenError
ImportError: No module named 'passlib.totp'
dpkg: error processing package pgadmin4-apache2 (--configure):
 subprocess installed post-installation script returned error exit status 1
Setting up python-passlib (1.7.1-1.pgdg16.04+1) ...
Errors were encountered while processing:
 pgadmin4-apache2
E: Sub-process /usr/bin/dpkg returned an error code (1)```