Not able to send multiple events with JS.push in phx-submit

I want to send multiple events to liveview on the form submittion. I am chaining two JS.push commands, but the server recieves only first_event.

    <.form :let={f} for={%{}} phx-submit={JS.push("first_event") |> JS.push("second_event")}>
      <button type="submit">Submit</button>
    </.form>

Event handlers:

  def handle_event("first_event", _params, socket) do
    dbg("Recieved first event")
    {:noreply, socket}
  end

  def handle_event("second_event", _params, socket) do
    dbg("Recieved second event")
    {:noreply, socket}
  end

Interesting thing is that if I click on the button which has phx-click, both events are send to the server.

<button phx-click={JS.push("first_event") |> JS.push("second_event")}>button</button>

Why does phx-submit behave differently?