For developers that know SQL and PL/SQL, no other framework is as empowering as Oracle Application Express (APEX). But not all developers know how to program using PL/SQL.
In order to provision Oracle Autonomous Database 21c, you will need an Oracle Cloud account in one of these regions: Germany Central (Frankfurt) - FRA, US East (Ashburn) - IAD, US West (Phoenix) - PHX or UK South (London) - LHR. If you currently do not have an account, you can create one here
and specify one of the regions above.