SQL> create table t ( x int primary key, y varchar2(10));

Table created.

SQL> create materialized view log on t with primary key;

Materialized view log created.

SQL>
SQL> create materialized view MV1
  2  refresh fast on commit
  3  as select * from t;

Materialized view created.

SQL>
SQL> create database link looper using 'db18_pdb1';

Database link created.

SQL> select * from t@looper;

no rows selected

SQL>
SQL> create materialized view MV2
  2  refresh fast on commit
  3  as select * from t@looper;
create materialized view MV2
*
ERROR at line 1:
ORA-12054: cannot set the ON COMMIT refresh attribute for the materialized view