EXQ Mocking for testing fails

Using Exq as below

test.exs

config :exq,
  name: Exq.Mock,
  # adapter: Exq.Mock,
  queue_adapter: Exq.Adapters.Queue.Mock,
  start_on_application: false

test_helper.exs
Exq.Mock.start_link(mode: :fake)

MyApp
Exq.enqueue_in(Exq, "sendbird", @time_delay, F, [x, y])

Tests

** (exit) exited in: GenServer.call(Exq.Mock, {:enqueue, #PID<0.1439.0>, :enqueue_in, [Exq, "sendbird", 3, F, [x, y], []]}, 30000)
        ** (EXIT) an exception was raised:
          ** (FunctionClauseError) no function clause matching in Exq.Manager.Server.handle_call/3

          The following arguments were given to Exq.Manager.Server.handle_call/3:

              # 1
              {:enqueue, #PID<0.1439.0>, :enqueue_in, [Exq, "sendbird", 3, F, [x, y], []]}

              # 2
              {#PID<0.1439.0>, [:alias | #Reference<0.2056019793.2766733316.7523>]}

              # 3
              %Exq.Manager.Server.State{dequeuers: %{"default" => {Exq.Dequeue.Local, %Exq.Dequeue.Local.State{current: 0, max: 100}}}, enqueuer: Exq.Mock.Enqueuer, metadata: Exq.Mock.Worker.Metadata, middleware: Exq.Mock.Middleware.Server, namespace: "exq", node_id: "MacBook-Pro", pid: #PID<0.1436.0>, poll_timeout: 100, queues: ["default"], redis: Exq.Mock.Redis.Client, scheduler_poll_timeout: 200, shutdown_timeout: 5000, stats: Exq.Mock.Stats, workers_sup: Exq.Mock.Worker.Sup}

          Attempted function clauses (showing 6 out of 6):

              def handle_call(:redis, _from, state)
              def handle_call(:subscriptions, _from, state)
              def handle_call({:subscribe, queue}, _from, state)
              def handle_call({:subscribe, queue, concurrency}, _from, state)
              def handle_call({:unsubscribe, queue}, _from, state)
              def handle_call(:unsubscribe_all, _from, state)

          stacktrace:
            (exq 0.16.2) lib/exq/manager/server.ex:183: Exq.Manager.Server.handle_call/3
            (stdlib 3.17.2) gen_server.erl:721: :gen_server.try_handle_call/4
            (stdlib 3.17.2) gen_server.erl:750: :gen_server.handle_msg/6
            (stdlib 3.17.2) proc_lib.erl:226: :proc_lib.init_p_do_apply/3

     stacktrace:
       (elixir 1.13.4) lib/gen_server.ex:1030: GenServer.call/3
       (exq 0.16.2) lib/exq/mock.ex:92: Exq.Mock.enqueue_in/6

Can anyone help me in how to use mock in exq for testing
I am having the above issue.
Am I missing some configuration or implementation of EXQ is incorrect ?
https://github.com/akira/exq