You are in the process of integrating your C4C system into the HANA Cloud Platform Portal Service. You are using the HTML widget and an iframe which points to the C4C URL. However, C4C cannot be displayed and it shows a technical error "Refused to display XXX in a frame because it set 'X-Frame-Options' to 'SAMEORIGIN'" (XXX represents the data).
SAP HANA Integration
SAP Cloud for Customer
Using the HTML widget and a iFrame that points to a C4C URL is not the best practice.
The option is to create a dedicated HTML5 application that points to C4C via destination. You can refer to: https://help.hana.ondemand.com/help/frameset.htm?39723061bc4b4b679726b120cbefdf5a.html.
This HTML5 app should be deployed to your Cloud Platform account.
Then, you can convert the application to a widget. Refer to the documentation: https://help.hana.ondemand.com/cloud_portal/frameset.htm?f5453954e6cc4dc59d6d16b3f584a841.html
Finally, you can add this widget to the page instead of using the HTML widget.
Dedicated HTML5 application means development of a custom ui5 application which consumes the C4C Odata service.
If your idea is to show the whole C4C Web site directly in the same page of the portal without opening another new webpage then it is a new feature request.
Iframe, url, x-frame options , KBA , AP-RC-UIF-FLX , Page Layout & Key User Configuration , How To