Are you able to connect to the Oracle server by creating an ODBC DSN using Control Panel on the SQL 2019 instance? If you are not able to connect using ODBC then troubleshoot that first.
Based on the error the listener on the Oracle server is OK, but you can verify that by using tnsping.
Another troubleshooting step is to check the listener status on the Oracle server and make sure on the list of services listed, the service name is listed as OK.
By the way. 13c does not exist as Oracle versions. Valid versions of Oracle are 12c, 18c, 19c and 21c.
One last thing you can try that should work, is to change the SERVICE_NAME=TEST by SID=TEST. On the Oracle server you can get the SID.