title: Power Automate: How to generate autonumber for every batch of new items in a sharepoint list
body: <p>Here is the process that I wish to give autonumbers which i would like to call ATSUB# and ATT#: ATSUB#0001 and ATT#0001-01.</p>
  <ol>
  <li>ATSUB Email is received and comes with attachments that ranges from 1 PDF and up.</li>
  <li>I already setup a Sharepoint list with the column ATSUB# ATT# and Email ID and Attachment ID.</li>
  <li>In this Sharepoint list, i would like the ATSUB# to increment per ATSUB email but the number of new items in the list depends on how many attachments there are in the ATSUB email.</li>
  </ol>
  <p>Let's say these are the ATSUB Emails in Outlook:</p>
  <ol>
  <li>ATSUB with 1 PDF on 3/1/2022</li>
  <li>ATSUB with 2 PFDs on 3/2/2022</li>
  <li>ATSUB with 2 PDFs on 3/2/2022</li>
  </ol>
  <p>The resulting Sharepoint list should look like this:</p>
  <div class="s-table-container">
  <table class="s-table">
  <thead>
  <tr>
  <th>DATE</th>
  <th>ATSUB#</th>
  <th>ATT#</th>
  </tr>
  </thead>
  <tbody>
  <tr>
  <td>3/1/2022</td>
  <td>ATSUB#0001</td>
  <td>ATT#0001-01</td>
  </tr>
  <tr>
  <td>3/2/2022</td>
  <td>ATSUB#0002</td>
  <td>ATT#0002-01</td>
  </tr>
  <tr>
  <td>3/2/2022</td>
  <td>ATSUB#0002</td>
  <td>ATT#0002-02</td>
  </tr>
  <tr>
  <td>3/2/2022</td>
  <td>ATSUB#0003</td>
  <td>ATT#0003-01</td>
  </tr>
  <tr>
  <td>3/2/2022</td>
  <td>ATSUB#0003</td>
  <td>ATT#0003-02</td>
  </tr>
  </tbody>
  </table>
  </div>
  <p>Thank you so much!!!</p>