I just accessed your site and found that you are using the dummy certificates we include in our stacks.
You also have other certificate files inside the /opt/bitnami/apache2/conf folder, do you want to use them now or do you want to generate new certificates?
Why do you say that the Bitnami WordPress solution doesn't support the Bitnami HTTPS configuration tool? Did you get any error message? The tool should work properly with this solution.