Can’t create diskgroup in Oracle 19c

I’ve successfully installed Oracle 19c with this article.

Now I need to restore the database from existing backups. I’ve first restored the control file, then I started to restore the database:

rman> restore database; ... ORA-19504: failed to create file "+DATA" ORA-17502: ksfdcre:4 Failed to create file +DATA ORA-15001: diskgroup "DATA" does not exist or is not mounted ORA-15374: invalid cluster configuration ... 

Then I tried to create the diskgroup, and it failed:

SQL> create diskgroup DATA external redundancy disk '/dev/loop1' force; create diskgroup DATA external redundancy disk '/dev/loop1' force * ERROR at line 1: ORA-15000: command disallowed by current instance type 

Is there a work around? I can either ignore the diskgroup or find a way to create one, I just don’t how to fix it.