error - "insufficient privilege: Not authorized'

Hello, I am trying to grant select access to myself to a schema that I have just created with the following command from developer guide:

call

_SYS_REPO.GRANT_SCHEMA_PRIVILEGE_ON_ACTIVATED_CONTENT('select','<schema name>','<user name>;

and I encountered the following error:

"insufficient privilege: Not authorized'

I think I need admin access to run the above command, is that correct? Can someone help me this resolve the error please?

Thanks in advance,

Suresh.