http2: how to make wso2ei 6.6.0 to use http2 protocl?

I'm using wso2ei 6.6.0, and my manager wants to set all requests to use http2, but I can't find a way to make wso2 use the http2 protocol. I'm aware that I can use a web server between them, but I need to make a passthrough to listen on http2.and also need to send all requests on http2 protocol; any idea how I can handle this situation?!