The new Windows browser Edge is a scaled-down security-based Internet browser with simple basic features.
Nevertheless, the Internetexplorer 11 is still available in Windows 10.
In the Edge click on "Settings", there is a tab or button with "Open Internet Explorer". As soon as you have opened it, click on the "Internetexplorer" icon in the quick start bar or button with the right mouse button and you get the usual option "tackle the program on the taskliste".
If you have done this, the Internetexplorer 11 in Windows 10 is attached to the Taskleiste.