How to pass paramater to report?

Now, I add menu item button on ReqTransPo(form) to print ReqTransOverview(report) for set the selected itemID as default.

I try to use

this.args().record().recid

to get the recid for reqPO(datasource), but it retrun the recid is the first record of InventTable(datasource).

How can I pass reqPO.itemid to report?

Thanks!