Problem: The option to store credentials is not available when adding secured services in ArcGIS Online
When adding an ArcGIS Server secured map service as an item in ArcGIS Online, ArcGIS Online does not provide the option to store credentials with service items, and users are unable to save credentials with the secured service. Instead, users must enter the credentials every time the map is opened.
There are a few potential issues that could cause this problem.
The service is stored on an ArcGIS Server configured with web-tier authentication. Credentials can only be saved to an item if the ArcGIS Server is configured with ArcGIS Server built-in security, which is token-based. If the ArcGIS Server is configured with web-tier authentication, the server URL must be added to the list of trusted servers (see Related Information for details). This enables credentials to be passed without an authentication request between ArcGIS Server and ArcGIS Online. However, there is no option to store the credentials in the service itself when adding it as an item in My Content.
The service may be stored on an internal-only server. A service must be externally visible on the internet for ArcGIS Online to store the credentials. When adding an internally secured service as an item to the My Content page, ArcGIS Online attempts to reach the internal Get Token page. ArcGIS Online is unable to validate the credentials if the service is not visible. If it is unsuccessful (if it is unable to reach the internal server), the service is not accessible and the option to store credentials is not provided.
The server is using Secure Sockets Layer (SSL) certificates that are not supported or are improperly configured. Self-signed certificates are also not allowed.
Solution or Workaround
List any web-tier authenticated servers on the list of Trusted Servers. This enables credentials to be passed without an authentication request between ArcGIS Server and ArcGIS Online. Please note that there is no option to store the credentials in the service itself.
Use only external URLs to utilize the store credentials functionality. Refer to the following ArcGIS Online help page, Add items, for more information.
Ensure a trusted Certificate Authority (CA) is being used, and all intermediate/chain certificates are set up correctly. Free online SSL checkers can be used to review SSL certificate validity.
If the problems persist, please contact Esri Support Services for additional help.