如何将rails ActiveStorage附件放入一个对虾pdf？

class CreatePdfAttachments < ActiveRecord::Migration[6.0]
  def change
    create_table :pdf_attachments do |t|
      t.string :name
      t.text :description
      t.timestamps
    end

    add_column :pdf_attachments, :attachment, :string
  end
end

class PdfAttachment < ApplicationRecord
  has_one_attached :attachment
end

<%= form_with(model: @pdf_attachment, local: true) do |form| %>
  <div class="field">
    <%= form.label :name %>
    <%= form.text_field :name %>
  </div>

  <div class="field">
    <%= form.label :description %>
    <%= form.text_area :description %>
  </div>

  <div class="field">
    <%= form.label :attachment %>
    <%= form.file_field :attachment %>
  </div>

  <div class="actions">
    <%= form.submit %>
  </div>
<% end %>

class PdfAttachmentsController < ApplicationController
  def create
    @pdf_attachment = PdfAttachment.new(pdf_attachment_params)

    if @pdf_attachment.save
      redirect_to @pdf_attachment, notice: 'PDF attachment was successfully created.'
    else
      render :new
    end
  end

  private

  def pdf_attachment_params
    params.require(:pdf_attachment).permit(:name, :description, :attachment)
  end
end

<%= link_to 'View PDF', @pdf_attachment.attachment.url %>