This has nothing to do with JL.
Gmail started requiring 2 step authentication and an app specific password for 3rd party connections.
https://myaccount.google.com/signinoptions/two-step-verification/enroll-welcome
Once you have it enabled
https://myaccount.google.com/apppasswords
Put in your password.
Then by the app drop down put in "other" and put in a name and click generate.
A one time password will popup, copy that and put that in JL as the email password.
You will only see this password one time.