By default, Traefik connects to applications backend via HTTP. If the application exposes it's WebUI via HTTPS then we will need to tell Traefik to use this protocol.
For Unraid, find the app that you would like to reverse proxy, once you are in the template, scroll to the bottom and click on the "Add another Path, Port, Variable, Label or Device". Select to add a label and fill in the fields as per the screenshot below.
Make sure to set this as a Label.
Copy and paste the following into the key: field, make sure to swap out app for the app name you are adding this to.
Tell Traefik which port to use for this app, simply add https to this field.
Click add and then apply to redeploy the app with the new label added to it.
WARNING
You must replace app with the name of your application that this label is being added to otherwise Traefik will see duplicates.
In some cases, you may find that after changing the scheme to HTTPS, you will have to also specify the application's HTTPS port manually. You can do this by following the short guide on "Proxying an App with Multiple Exposed Ports".
PLEASE NOTE
You can add multiple of these labels at once before finally deploying your application.
Traefik will now use the HTTPS protocol specified to forward all traffic onto the app correctly. Now when you deploy your application, you will be able to visit it by going to your domain with the app name as the subdomain (APP-NAME.DOMAIN.COM).