Microsoft is working to improve the Surface Pen (Digital Pen) experience on its Chromium Edge browser. A commit at the Chromium Gerrit suggests that soon Pen click in editable field with digital pen will invoke keyboard.

Currently if you click in an editable field in the Edge browser with a pen it does not invoke the virtual Windows 10 keyboard. But this change adds pen clicks as a triggerable event for invoking the virtual keyboard on Windows.

As noted in the commit,

Pen click in editable field with digital pen invokes keyboard Currently, clicking in an editable field with a pen does not invoke the virtual keyboard as is expected per Microsoft standards described here https://support.microsoft.com/en-us/help/4057757/windows-10-get-to-know-the-touch-keyboard This change adds pen clicks as a triggerable event for the virtual keyboard on Windows