Unable to connect user from SQL Developer to AWS RDS - oracle

Question

I tried to connect to an AWS RDS that I created. I used SQL Developer to add the connection. I used the default SYSTEM user of Oracle. I have configured my tnsnames and listener files by adding the following entries.
LISTENER
LISTENER =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1522))
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1522))
)
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = final.c3ixwyhkuph6.ap-south-1.rds.amazonaws.com)(PORT = 1521))
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1522))
)
)
TNSNAMES
FINAL =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = 'final.c3ixwyhkuph6.ap-south-1.rds.amazonaws.com')(PORT = 1521))
(CONNECT_DATA =
(SERVER = DEDICATED)
(SERVICE_NAME = final)
)
)
LISTENER_FINAL =
(ADDRESS = (PROTOCOL = TCP)(HOST = final.c3ixwyhkuph6.ap-south-1.rds.amazonaws.com)(PORT = 1521))
As you can see from this screenshot
AWS RDS Description Screenshot
the hostname is 'final.c3ixwyhkuph6.ap-south-1.rds.amazonaws.com', and the port number is 1521. Also, the SID here is 'final'. These have been added correctly by my above TNSNAMES and LISTENER entries.
However when I attempt to connect, I get the following
Error on SQL Developer
Status Failure -Test failed: IO Error: The Network Adapter could not establish the connection.
What could be the source of the error?

Answer 1

Make sure that your SID in SQL Developer is your database name on AWS and that you are using the correct username. In your screenshot, you have it as SYSTEM but the default username on AWS is admin. Go to the Configuration page in AWS and verify the highlighted portions in the screenshot below:
Assuming your DB Name in your Configuration page above is indeed "final", you should be selecting the SID option instead of Service name in SQL Developer, and inputting "final" as demonstrated in the snippet below.