SSMS Linked Server -ORA-28009: connection as SYS should be as SYSDBA or SYSOPER (Microsoft SQL Server, Error: 7303)

Question

How could I use "Linked Server" from SSMS IDE to connect the Oracle server database with "SYSDBA"?

I've tried many methods as following to show you what I did right now:
Oracle client connect to Oracle Server data:

SSMS connect to Oracle Server data:

More testing information
I also use "SQLPLUS" to check tnsnames.ora the file is okay or not but the answer is as following

1. sqlplus SYS/Oradoc_db1@DBNAME as SYSDBA <-- is okay
2. sqlplus SYS/Oradoc_db1@DBNAME <-- Error

Answer 1

I found the problem and you can follow my steps to fix this issue.
1. Don't use SYS to be your USERID
2. Add new USERID

-- CREATE USER SQL
1. CREATE USER a
2. IDENTIFIED BY a
3. DEFAULT TABLESPACE "USERS"
4. TEMPORARY TABLESPACE "TEMP";
*** <-- if you got the error, please follow above content to fix problem
 (SQL> alter session set "_ORACLE_SCRIPT"=true;  )
-- ROLES
GRANT DBA TO a;