With the CNAO setup, why the General Ledger line is not enforced to input the Cash Flow Items?

I have setup the CNAO as the guide. When testing the Cash In or Out from General ledger by creating journals, it is not fored to input the Cash Flow Items. The journal can be saved and posted without Cash Flow item.

It is not appropiate.

Is there expert who can tell me the missing setup?

在用CNAO做现金流量表的时候，设置做完以后，总账凭证行上面选了银行科目以后，可以保存、过账，都不会提示没有录现金流量项目。