Custom panel not visible in Deal page

Team,

I created a public Pipedrive app and added a custom panel extension. All the necessary details for the app has been updated like scope, redirect uri.
When I clicked the “Install & Test” button, it prompted me to allow permissions, and after I did that, it redirected me to the specified redirect URI. My app server responded with a 200 status for that URL. However, after completing the process, I couldn’t find the custom panel on the Detail page of a deal to check it.

Let us know if anything needs to be done

Below are details of my account:
Email: integ@buyerstage.io
App Name: Buyerstage Development
App type: public
Custom panel name: Buyerstage Dev Custom Panel
Panel location: Deal details

Hi,

At first look, it feels your app didn’t complete the code exchange to OAuth tokens. When OAuth server redirects to a specified redirect URL it should contain code query param, which has to be used to retrieve an access token. Check our documentation for more details OAuth authorization

After your app completes installation process by retrieving the access token, the app extension will become available at the desired placement.

Best regards,
Pavlo