Making custom tel protocol windows 10

[Greenwood]

I'm working on a custom softphone application and running into a problem. I would really like to redirect the tel: links to a application on my PC. I have figgured out I need to add my application to the windows TEL; URL:tel option list. However all solutions I'm finding don't seem to work. This documentation isn't working for me (yes i have restarted multiple times) some peaple say it isn't posible in windows 10 annymore, however there are a few third-party application that are popping up. The applictions are not from the windows store so that can't be the issue either.

The .reg export I ended up with looks like this:

Windows Registry Editor Version 5.00

[HKEY_CLASSES_ROOT\tel]
@="URL:Tel test"
"URL Protocol"=""

[HKEY_CLASSES_ROOT\tel\DefaultIcon]
@="C:\\Test\\Test.exe"

[HKEY_CLASSES_ROOT\tel\shell]

[HKEY_CLASSES_ROOT\tel\shell\open]

[HKEY_CLASSES_ROOT\tel\shell\open\command]
@="C:\\Test\\Test.exe" "%1"

I would really appriciate anny tips towards the solution.

[Gizmo]

Hi, I'm not familiar with setting this up, but can hopefully help, I found some info on the page below:
https://superuser.com/questions/1112229/cant-change-tel-protocol-handler-in-windows-10

   Here are my thoughts:

First of all, are there supposed to be two back slashes  \\  when you are referring to a file destination? Windows only has a single  \  in filenames -
You used:
@="C:\\Test\\Test.exe"

Shouldn't it be:
@="C:\Test\Test.exe"

I read through all the code on that page, and there is a double backslash \\ used, but not for a filename, it looks like its for how you set the Dialler name in the registry

Also, when you replace @="dialer %1" with your filename, I don't think you keep the %1 part, so it just becomes @="C:\Test\Test.exe"

Hope this may be some help.