Our documentation says the following:
Browsing to http://DOMAIN should result in the load balancer displaying the insecure welcome page of the Bitnami application.
Browsing to https://DOMAIN should result in the load balancer displaying the secure welcome page of the Bitnami application. Clicking the padlock icon in the browser address bar should display the details of the domain and SSL certificate.
My question is, do you want to redirect all the traffic to HTTPS or do you mean that browsing to https://DOMAIN is not working as expected? In case you want to force HTTPS, this case could help: