Go to your Windows icon and then start typing the word Default.
Click ‘Choose default apps by protocol
Scroll down to SIP
Set they two options for SIP and SIPS to Microsoft Teams as show here.
Lastly scroll down and change TEL: to Microsoft Teams.
Now when you dial from your web Outlook or your normal Outlook the request will go to the Microsoft Teams client.
You May get a pop-up from your web browser asking you to confirm the program to make the call. Be sure to have it remember your choice.
This is an example of what you will see as an outlook contact. This will help you dial your companies shared external contacts or your personal contacts.
Depending on your web browser, you may get this, or it may dial automatically for you.