Experience Builder CORS Issue

[LIZDean]

We have some WMS layers coming from an external source and if I load them into a web map in ArcGIS Online they load fine with embedded credentials. I then added that web map to an experience builder app and the layers do not load.

We get the CORS Issue below and just want to see if what options we have.

[TimWestern]

You may need to check to see if the app client you created in the portal area has a redirect to map it as a valid destination.  

[Junshan_Liu]

Can you add the experience.arcgis.com domain into your org allow origins to give it a try? The setting is at: Organization -> Settings -> Security -> Allow origins

[ShaneONeill_144]

Making sure to remove any trailing backslash in the URL for your Portal's "allowed origins" security setting, as described in the documentation below:

Restrict cross-domain requests to your portal https://enterprise.arcgis.com/en/portal/latest/administer/windows/restrict-cross-domain-requests-to-...

For example, if you add your machine's URL to the the "allowed origins" as follows:
https://MyMachineName.domain.com/

This will cause the CORS error when trying to run Experience Builder. Make sure to change this URL to:

https://MyMachineName.domain.com