From Pro you can publish your web layer.
You can then customize and publish your web map from Pro.
However, is there a way to make changes to the Web Map in Pro and then overwrite what is already there without having to delete it first?
Hi Robert - see this thread ArcGIS Pro - Update existing webmap You can up vote but more importantly, please comment about what changes in the web map you expect to make. It seems like the majority of users simply want to update symbology, but there could potentially be many other changes made to a web map opened in Pro and we are interested in better understanding user needs and expectations.
Ideally ANY change.
Adding additional services or removing services, changes to pop ups, disable or enable editing etc..
Retrieving data ...