Create point feature with line in AGOL

[MarlaJohnson]

I need to use a line feature for field maps but want to display it as a point and line feature on an AGOL map.  Are there anyways to do this? I also need to automatically generate the Lat and Long of the line. 

[AndreasHall]

With ArcGIS Pro you could create a custom symbol using Solid Stroke and Picture Marker and publish that as a Web Style to ArcGIS Online. if you have access to Pro I could provide som more details if you want.

Here is an example of a custom Web Style I have created that symbolizes a polygon as both a polygon and a point. The same should be possible for lines. 

Another solution would be to use Find Centroids (Map Viewer)—ArcGIS Online | Documentation to convert your lines to points.