Smart Forms is primarily aimed for use on small personal sites and for testing. It’s not customisable, and all of the backend work is done on Bootstrap Studio’s servers.
If you would like something more complex or customisable, you will need to look into coding your own solution and hosting your site externally, and not on Bootstrap Studio’s hosting.
Their are tools like EasyForms you can run which help you creat PHP forms and the like.
There could be solutions for extracting the information from your emails and putting it in a database, but I can garentee it would be far more work than making your own PHP form.