Fetching Apollo Server on Heroku return "forward is not a function"
I think, if you sending GraphQL queries to a REST endpoint (that's what I assume from RestLink usage) you may need to change slightly your queries.
You may find the examples here; https://www.apollographql.com/docs/link/links/rest/#quick-start
@rest directive is used within the queries to specify the end point. Like following;
const query = gql` query luke { person @rest(type: "Person", path: "people/1/") { name } }`;
I don't know how your backend is designed and I have never used GraphQL with REST backend but I hope it is helpful.
If your backend is not a REST service may be you should not use RestLink and simply specify the URI within the ApolloClient constructor.