Hello All,
I am trying to load my layers from arcgis server rest service URL.In my code i set the custom popup info for feature layer.this feature layer i want to load when first time experience builder load base map.I want to check Base map load.After this i want to add my feature layer on the webmap view.
In the Experience Builder environment, it is impossible to add any code without creating a custom widget to put it in.
The most common and best way to add a featureLayer in Experience Builder is to create a webmap in your ArcGIS Online/Enterprise portal and then import that webmap using the Map Widget.
Here are some helpful tutorials if you are new to Experience Builder. https://learn.arcgis.com/en/paths/try-arcgis-experience-builder/