you will need a little guide, because microsoft edge is a bit tricky.
it can not be launched directly by running microsoftedge.exe "path_to\yourfile.html" as it is done using internet explorer, firefox and chrome.
instead we will have to make shell api calls.
but that’s not difficult, once you’ve read this guide.

step by step guide - how to add “launch in edge” to notepad++:

• open the folder %AppData%\Notepad++\ in explorer

• find the file shortcuts.xml and open it in notepad++ for editing.

• copy the following line and paste (insert) it anywhere inside the <UserDefinedCommands>section

<Command name="Launch in Edge" Ctrl="yes" Alt="yes" Shift="yes" Key="69"> shell:Appsfolder\Microsoft.MicrosoftEdge_8wekyb3d8bbwe!MicrosoftEdge $(FULL_CURRENT_PATH)</Command>

• now your shortcuts.xml should look like the screenshot below (plus your ie and other user defined commands):

• save shortcuts.xml and restart notepad++
  (exit and reopen notepad++ to activate your shortcut changes to the run menu)

• if you now run “launch in edge” on any file, edge will open and display it, as seen at the screenshot below:

note: you can also use the keyboard shortcut ctrl+alt+shift+eto launch edge with your file

good luck and happy html coding 😉👍

You can change it yourself by editing shortcuts.xml appropriately (use the existing entries as examples to create a new one).