How to expose Etags from the response header of VBCS endpoints on a vbcs page ?

Summary: how to access etags in custom headers since it is returning empty response header fields, or if it is possible to move the etag to the response body?

Content (please ensure you mask any confidential information): In service connection endpoints , when we receive a response body along with response header, there is a etags generated for that request. We want to display the response header etag on a vbcs page on a button action event. Currently the response header is empty when we try to map it in an action chain. How to display the etag on vbcs page when user click on button action chain calling the rest endpoint ?