Dynamic forms with nested attributes in rails

I am using some tutorial to create a dynamic form in which i should be able to add json object array of amounts.

i should get this params from form

quote_amounts: [
  {"kind"=>"website", "label"=>"Website", "amount"=>10000.0}, 
  {"kind"=>"website_review", "label"=>"Website Review", "amount"=>12000.0}
]

I have created created the controller in this way

def create
    @quote.assign_attributes(quote_params)
      if @quote.save
        @quote.submit_quote
        @name = @quote.contact.user.display_name
        redirect_to confirm_form_submission_path
      else
        render :new
      end
  end

and

  def quote_params
    params.require(:vendor_quote).permit(:notes, quote_amounts: [])
  end

and I have created this form

            <%= f.number_field :amount, min: 0, prepend: '$', required: true %>
            <%= f.text_field :label, required: true %>
            <%= f.text_field :kind, required: true %>
            
            <%= f.text_area :notes %>

            <%= f.submit "Submit quote", class: "btn btn-info btn-lg btn-block btn-rounded text-uppercase" %>

by this i am getting this error

undefined method `amount' for :amount

and please tell me that how to add 'add more' button so i can add multiple quote_amounts and save it into one json array object in single form.