Datasource with Web connection error in Report Server

[SANDRALIA]

Hi Friends! 
I load a table from "https: //   bna.com.ar" , I can see ok in the report but when is uploaded to PBI Report Server (optimized for reporting), show error. (see msg at bottom)

I tried in anonymous way, and also fixing windows credentials in the report but always is rejecting in Report Server datasource administration. 
Can somebody help me please?

Couldn't connect

The report server couldn't connect to the data source using the information you entered. Make sure you've entered the connection string and any credentials correctly.
The remote name could not be resolved: www.    bna.com.ar 

[aduguid]

I would setup a domain user that has access to the site and use that in the connection string.

[SANDRALIA]

thank you @aduguid ,  it's a public web page...  In cannot setup an user with this domain..
What Im doing wrong?

[aduguid]

The user in the connection string would need permissions to access the site. You can try with your user name and password as a test. If it works then I would have your infrastructure team setup a domain user "service account" on your network that then can access the site. You can test with the service account by holding the shift key down right click on Microsoft Edge. Then you can "Run as different user" and enter the service account.