Update Gupshup Setup with username retrieval instructions (#564)

Added instructions for retrieving Gupshup username.

Author: SangeetaMishr

docs/2. Pre Onboarding/02. Gupshup Setup.md

@@ -3,7 +3,7 @@
   <tr>
     <td><b>10 minutes read</b></td>
     <td style={{ paddingLeft: '40px' }}><b>Level: Beginner </b></td>
-    <td style={{ paddingLeft: '40px' }}><b>Last Updated: October 2025</b></td>
+    <td style={{ paddingLeft: '40px' }}><b>Last Updated: January 2026</b></td>
   </tr>
 </table>
 </h3>
@@ -239,3 +239,18 @@ This is something internal and not visible to your end users & also **it cannot
 
 - Your WhatsApp chatbot will stop working immediately.  Please reach out to the Glific Support Team on [Discord](https://discord.gg/gYHMRGQVpT) .
 
+7. How to Find Your Gupshup Username ?
+
+If you forget your Gupshup username, you can request it from the Gupshup support team by email. Here’s how:
+
+- Send an Email to partner.support@gupshup.io mark a copy to Glific Support Team (to help speed up the process)
+
+- Include the Following Details
+
+    - Your organization name
+
+    - Your Gupshup app name (find it in your Glific instance: Settings → Gupshup)
+
+The Gupshup team will reply with your username and any guidance, within 24 hours.
+
+**Tip:** Save your username once you receive it to avoid requesting it again.