Open MFA enabled SharePoint Online site with SharePoint Designer 2013

If your tenant has multi-factor authentication turned on, your Internet Explorer was disabled, with Edge as default browser, and you were trying to use SharePoint Designer 2013, you will encounter the error shown below.

"The Web Server does not appear to have any authentication methods enabled. It asked for user authentication, but did not send a WWW-Authenticate header." 

This was because Office 2016 and Older Versions use Basic Authentication method.

As SharePoint Designer 2013 was part of Office 2013 clients, and to overcome this, you need to enable Modern Authentication.

To enable modern authentication for any devices running Windows, you need to set the following registry keys. 

Once the above Registry Keys were added with Hexadecimal value 1, then it should look as shown below.

Open the SharePoint Designer 2013, Go to Account. It should show your login info.

 Now try to open the SharePoint Online Site Collection, it opened like charm.