Oracle throw "no snapshot found based on specified time" when running flashback query

i found in debezium-oracle connector 0.9.5-final code OracleSnapshotChangeEventSource.java line 111

Optional<Long> latestTableDdlScn = getLatestTableDdlScn(ctx);

my last_ddl_time in the table is very old when i run this line it will throw
ORA-08180: no snapshot found based on specified time
ORA-06512: at "SYS.TIMESTAMP_TO_SCN", line 1

is any way to avoid this error?

Thanks