CORS error with ExB Developer Edition and Enterprise

[MarcBate]

When accessing ExB Developer edition via https://localhost:3001, and entering our ArcGIS Enterprise 10.9.1 address on the page https://localhost:3001/page/set-portalurl , it says "Your application domain is not allowed via Cross-Origin Resource Sharing (CORS) to access" then url of our portal web adaptor.

I tried to allow localhost in the Organization > Settings > Security page in the Portal, but it won't let me add it or https://localhost:3001

How do we use ExB Dev with our Enterprise server? I can only get it to work with AGOL.

[DougSims_GT]

"I can only get it to work with AGOL."

I'm still getting this error even using AGOL. 

Even after adding my machine's FQDN to the allow list, I still get the CORS error when trying to register the app on my desktop.

Am I missing something obvious here? 

[ADM48]

Yup same here.  My application is in AGOL and I've added the domain to the allow list.  

[DougSims_GT]

The first problem I had was that I entered my server and my desktop into the list of "Trusted Servers" instead of the "Allowed origins" section. 

I had originally added our top level domains to the allowed origins list, thinking that would cover all of our servers, but I discovered that domain wildcards are not allowed in that list. (Which seems like an odd limitation.)

Adding my server name and my desktop FQDN to the allowed origins list fixed the issue for me.