Not able to email dashboards in superset

[i4vijay]

I have installed superset in AWS EC2 instance which is Ubuntu. It is working fine but i have a requirement to send dashboards in email to clients. I have configured SMTP, chrome browser, chromedriver, Redis and also made correct changes to config.py file. I am able to run celery worker, celery beat but if i try to send test email i am getting UnboundLocalError: local variable 'options' referenced before assignment in celery worker. This is so frustrating in superset. Why is it so difficult to enable this option in superset?

Also I tried with firefox and geckodriver and facing the same issue. All required installation are in correct path variable.
Either i get the above error or devtoolsactiveport file doesn't exist error.

What am i missing here? What is the correct way to enable email scheduling in AWS EC2 instance(Ubuntu)?
Did anybody faced the same issue? If so can someone please help me fix this issue