idを特定の一つにしたい

画面上のエラー
activeRecord::RecordNotFound in TimersController#update
Couldn't find Timer without an ID

ターミナル上
Started PUT "/bbotan" for ::1 at 2021-09-07 11:06:51 +0900
Processing by TimersController#update as HTML
  Parameters: {"authenticity_token"=>"[FILTERED]", "timer"=>{"timer_id"=>"21 999 1000 1001 1002 1003 1004 1005 1006 1007 1008"}, "commit"=>"bbotan"}
Completed 404 Not Found in 1ms (ActiveRecord: 0.0ms | Allocations: 666)

html該当のページ
<div class="botan">
<%= form_with model: [@timer],url: '/bbotan', method: :put, local: true do |f| %>
    <%= f.hidden_field :timer_id, :value => @timer.ids %>
<%= f.submit "休憩" %>
<% end %>
</div>

コントローラー
class TimersController < ApplicationController
    def index
    end
    def new
      @timer = Timer.new
      redirect_to
    end
    def index2
      @timer = Timer.all
    end
    def create
      @timer = Timer.create
      @timer.abotan = Time.now
      @timer.bbotan = Time.now
      @timer.cbotan = Time.now
      @timer.dbotan = Time.now
    if @timer.save
      redirect_to
    else
      render :index
    end
  end
  def updatebbotan
    @timer = Timer.find(params[:id])
    @timer.bbotan = Time.now
    if @timer.save
      redirect_to
    else
      render :index
  end
end

ルート
get 'abotan' => 'timers#index2'
post 'abotan' => 'timers#create'

  get 'bbotan' => 'timers#index3'
  put 'bbotan' => 'timers#updatebbotan'