no.
You host you domain at the web hosting provider.
Then you point the A reccord to bubble, so that the main domain: yourdomain.com will load bubble as it would normally do.
Then, you use the wildcard to load bubble’s content inside your subdomains, in iframe, because EACH subdomain will be generated with: php file that will load the data from bubble, full screen in iframe.
If your bubble page would be your bubbleapps.io/THIS, then your subdomain will be THIS.yourdomain.com.
That subdomain will load a PHP file that will load bubbleapps.io/THIS content, as a fullscreen page. Like the content is on THIS.yourdomain.com and not on bubbleapps.io/THIS.
Does this make sense now?