Hello All,

As mentioned below link we can disable popout for custom utilities

https://help.salesforce.com/articleView?id=sforce_api_console_lightning_utility_popout.htm&type=5 (https://help.salesforce.com/articleView?id=sforce_api_console_lightning_utility_popout.htm&type=5)

But how to disable Pop-Out  in  Standard Utilities - Open CTI Softphone ?

I tried the above solution provided in link but it is not working for Open CTI Softphone.