Unfortunately, the app's Home screen page does not have a delete feature to delete individual numbers or call history. Our apologies for the inconvenience.
As a workaround, you can try clearing the history or deleting individual numbers from your mobile phone's actual call log. After doing this, please go to the app's Help page and select the Check for Updates option.
You should now see that those numbers you deleted from your mobile phone's call log no longer show up on the app's Home page.