Adding slow motion - Windows 10 editor

[idontknowwhatimdoing]

I'm basically trying to add slow motion effects to some videos and the built in video editor in Windows 10 has this feature when you edit a video in the photos app. The issue is it only allows me to add the super slow motion effect for a few seconds when selecting the turtle icon. When I select the speed in the middle, it will allow me to add slow motion for pretty much the whole video but, it's too quick for what I want. Is there any way to make the super slow speed last longer or at least be able to get somewhere in between? It seems like you can only pick one or the other. If not, are there any programs available which will let me ad that super slow effect for longer periods?


Here's what I'm talking about:

[TreeTops]

Try it using what worked and make a file then open it again with this program and slow it down again.