Have a problem about adding data to datagridview

Hello, we are using Visual Studio 2017 and we have a problem about datagridviews. In first picture we have a form1 that contains datagridview and Mallar button which opens form2. In form2 we have to datagridviews and some buttons. First datagridview is connected to SQL and gets goods list from it. When we click to any good it sends a copy to datagridview2. After we choose all goods from datagridview1 we press OK button. When OK button is pressed it must send selected goods in DGV2 to DGV of form1. We can do it when dgv of form 1 is not connected to any data source. But we must connect it to datasource because we need to edit or add extra goods to written documents. When we try to do this we get a error "rows cannot be programmatically added to the datagridview when the control is data-bound". You will get reward for your help. Thanks in advance