getFocusedTab (JavaScript API Reference) for Dynamics 365 Channel Integration Framework 2.0

Returns the focused tab's identifier in a focused session, if the session belongs to the channel provider.

Microsoft.CIFramework.getFocusedTab().then(successCallback,errorCallback);

Promise with the value as String

Microsoft.CIFramework.getFocusedTab().then(
function success(result) {
console.log(result);
// perform operations on tab id value
},
function (error) {
console.log(error.message);
// handle error conditions
}
);