Mocking req.company.data[0].id object for MochaJS tests

Question

I have a product id and that way it can be used for request.

req.product.data[0].id 

What should I write here when I want to test it with mocha .set('---------')?

chai
  .request(server)
  .post("/login")
  .auth(token, { type: "bearer" })
  .set("req.product.data[0].id ", 1)
  .end((err, res) => {
    

    done();
  });