I have just added a DrawGizmo event node and have attached for you here the node as well as another required file modification. Once you import the packages you will be able to see and add the node “Events/Objects/DrawGizmos”.
Please note however that to be able to call Gizmo methods/functions, you will also need to add the type named “Gizmo” to the Preferred Types Editor. Once you do that you will be able to see and add Gizmo functions under the “Functions/Reflection/Gizmo” category in the node browser.