HOW TO
In Portal for ArcGIS, adding a secure ArcGIS Server service as an item without storing its credentials prompts for the login each time it is accessed. Storing the credentials for services in Portal for ArcGIS enables future usage without the login prompt.
The instructions provided describe how to create a public web map without the login prompt in Portal for ArcGIS using a secure service added from the web.
https://tiledbasemaps.arcgis.com/arcgis/rest/services/<serviceName>/<serviceType>
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