If you are in the GstarCAD Classic workspace,

Method 1

Find View > Viewports > New Viewports … , as shown in the following picture,

After you select the “New Viewports…” in the drop-down list above, a Viewports window will pop up, as shown in the following picture,

Method 2

A more convenient way to create a new layout viewport is to enter “Viewports”, as shown in the following picture,

Then press Enter key and the Viewports window will also pop up, the same goes for the 2D Drafting workspace.

If you are in the 2D Drafting workspace,

Find the Layout tab, as shown in the following picture,

You can click the Named button, as shown in the following picture,

Then the Viewports window will pop up, as shown in the following picture,

Here in this Viewports window, you can either create new viewports by clicking the New Viewports tab or make changes to the named viewports in the Named Viewports tab.