Bitnami solutions do not ship CPanel. You would need to install CPanel -following the official guides - and activate your license. If you have any questions regarding installing it I recommend asking in the official support channels:
The following guide has information about configuring a custom domain:
Can you try installing it following the steps in this guide?
Which exact message? Can you paste it here?
We have a Support Tool that will gather relevant information for us to analyze your configuration and logs. Could you please execute it on the machine where the stack is running by following the steps described in the guide below?
How to Run the Bitnami Support Tool
Please note that you need to paste the code ID that is shown at the end.