Bitnami developer here.
The Bitnami info page provides information about the installed application resources as well as useful links to documentation. It is accessible by clicking in the Bitnami banner in the right bottom corner.
In case you want to remove the banner, you will just need to SSH into your machine and then execute the following command:
sudo /opt/bitnami/apps/wordpress/bnconfig --disable_banner 1
Sometimes, it may happen that the bnconfig is disabled so you need to use this command instead
sudo /opt/bitnami/apps/wordpress/bnconfig.disabled --disable_banner 1
Please note that /opt/bitnami is the default installation directory of the Bitnami stack.
Finally, you need to restart Apache.
sudo /opt/bitnami/ctlscript.sh restart apache
You will find more information about the Bitnami banner using the following link:
https://docs.bitnami.com/general/components/bninfo/
EDIT:
It might happen that you moved the bnconfig tool when configuring the domain for your WordPress site. Do you have any bnconfig.disabled file in the /opt/bitnami/apps/wordpress directory? If so, please use that file when running the command above.
Regarding the banner, you can remove it manually by running the following command
sudo touch /opt/bitnami/apps/bitnami/banner/disable-banner
Apache looks for that file when adding the banner and it disables the banner if the file exists.