Please note that, as mentioned, a membership to Apple Developer Program would be needed to have your app on the App Store.
This is also indicated here (RAD Studio 10.4 wiki, page Joining the Apple Developer Program)
http://docwiki.embarcadero.com/RADStudio/Sydney/en/Joining_the_Apple_Developer_Program
Regarding Apple Developer Program, it would be beneficial also to read this page, section Distribution
https://developer.apple.com/programs/whats-included/
Then, once logged-in at https://developer.apple.com, you should find item "Certificates, IDs & Profiles" under Program Resources, please see screenshot.
Once "Certificates, IDs & Profiles" is selected, a page regarding pertinent items (e.g. Certificates, Identifiers, Devices, Profiles) is shown.
For additional information please also consider:
http://docwiki.embarcadero.com/RADStudio/Sydney/en/IOS_Mobile_Application_Development