const client = new ApolloClient({
  uri: 'some url',
  request: async operation => {
   const token = 'MvHE4SXPDa17yzh6Shswhsvwhswdwvd';
   operation.setContext({
     headers: {
       authorization: token
     }
   });
  }
})

const client = new ApolloClient({
  uri: 'some url,
     headers: {
       authorization: token
     }
   });