In case you wish to set up HTTPS access to Redash, and your Redash installation is setup.sh based, you can simply update the nginx config file located at /etc/nginx/sites-available/redash  with SSL configuration.

You will also have to upload the certificate to the server, and set the paths correctly in the new config.

In case of installation without Nginx as proxy - you have to set up something similar to nginx / httpd by yourself, and add the necessary ssl config.