I built an app that has multiple navigation tabs. Each tab refers to a map that resides in Portal for ArcGIS on-premise. The maps are displayed in the app using the ArcGIS API for JavaScript 3.18 using the esri/arcgis/utils AMD. When each tab is clicked, the page asks for the ArcGIS Portal credentials. I want the user to log in once on the main page and be able to view the maps without having to log into the Portal for ArcGIS account. How can I be able to do that? Thanks