Set request header in apollo-server

Hi there,

I’m a little bit confused with adding request Header.
Since the browser sends requests to the apollo-server first and then apollo-server sends to the backend;
and backend sends response to the apollo-server first and then to the browser, I want to add some request headers like (token) and response-headers (like set-cookie) by the apollo-server.

set-cookie works, but add request header doesn’t.
i tried to use datasouce but in this way i need to rewrite every resolver one by one.
(all the resolver are generated by openapi-to-graphql)

Can you please help on this?