In the developer portal under Environments → Custom Domains you are able to add your TLS/SSL certificate which you acquired through for example CloudFlare, GoDaddy,...
Afterwards you are able to go to your environment details for the environment you would like to activate a custom domain and under ‘network’ add the domain name with the above added certificate. Under ‘Runtime’ you can then add custom Runtime settings for the applicationrootUrl.
When restarting your application the changes should take place
For further explanation you can check:
Done with all above configuration, but showing 403 forbidden error>
Can you help where exactly am i missing??