how to create external ID for qweb / form creation in UI and without coding at all

1/. when you create a views or duplicate from an existing view, you will see no external id. In this situation, you will get an alert when you go to use this view or qweb.  

2/. Go to tree view, select the newly created item and export it. 

3/. When you go back to the view / qweb that you just exported, go to metadata