Cant Grant to _SYS_REPO

I have created a schema and tables using the SYSTEM user. Now I try to grant

GRANT SELECT ON SCHEMA FUJBPPOC TO _SYS_REPO WITH GRANT OPTION;

but get an error

Could not execute 'GRANT SELECT ON SCHEMA "FUJBPPOC" TO _SYS_REPO WITH GRANT OPTION' in 2 ms 360 µs .

SAP DBTech JDBC: [258]: insufficient privilege: Not authorized

Can someone guide me on this error?

Thanks