Keila - Open Source Mailchimp Alternative Built in Elixir!

Hi, getting this set up and generally got it working. I’m having an issue with keila embedding the port into the Unsubscribe link i.e.:

http://keila.example.com:4040/unsubscribe/p_GX8qGEZd/c_GX8qGEZd

so when the user clicks on it they see:

An error occurred during a connection to keila.example.com:4040. SSL received a record that exceeded the maximum permissible length.

Error code: SSL_ERROR_RX_RECORD_TOO_LONG

I understand that this is an phoenix config setting but I set up using the docker image so I don’t think I can tweak that, or am I wrong? regards,
Michael