I configured my popups in ArcGISPro, then published to ArcGIS Server, then imported the REST URL to a map service in AGOL, but the popup configurations are ignored. Is there a workaround without having to configure the popups in the webmap?
Popups are not stored on the service but at the layer item level or the web map level depending on what you are sharing from Pro. So using the URL to the REST endpoint will contain no popup info. If you had that service in pro and shared a web map to ArcGIS Online the web map would contain the popup info that Map Viewer and other apps would use.