Why can't I connect WebStorm 11.0.3 to Visual Studio Online (TFS)?

I have been trying for over a year to connect WebStorm (or any other JetBrains product) to my Visual Studio Online TFS code respository.

I can connect with Visual Studio 2015 to that same Visual Studio Online code repository with zero issues.

Here's what I've tried so far:

Install the TFS VCS plugin.

Follow the instrucions at https://www.jetbrains.com/webstorm/help/tfs.html

Address: https://myname.visualstudio.com/

Auth: alternate

username : myemail@verizon.net

password:  mypassword

save password checkbox: checked

click OK

Error: Transport error 401 unauthorized

variations of the above that also fail with unauthorized:

Address: https://myname.visualstudio.com/DefaultCollection

The work-around is to have both Visual Studio 2015 and WebStorm open at the same time, doing all VCS operations through Visual Studio.

What "magic trick" is necessary to get WebStorm to use my Visual Studio Online TFS account ?  I can connect with Visual Studio 2015 to that same Visual Studio Online code repository with zero issues.

I don't want to go another year without figuring this out.