Good day, @suraj.joshi. Can you brief us more on which app you are trying to integrate? The UI space is determined by how the app is coded. Sometimes, the app would be accessible in the sidebar (majority of the call widget cases) or in the ticket details page. 

Kindly give us more context on what app you are integrating which would aid us in checking the feasibility at our end. 

Meanwhile, here are a few third-party caller apps in Freshworks marketplace: 

https://www.freshworks.com/apps/freshdesk/3cx_click_to_call

https://www.freshworks.com/apps/freshdesk/aircall_for_freshdesk

Have a good day! 

Hi @Keer 

Thanks for reverting back.

We are integration a Mitel app and are in process of developing the same. Therefore, wanted to know that if the calling window can be floating on it will remain fixed in the sidebar? 

I look forward to hearing from you.

Thanks

Suraj