How to make a Level Template? All of the guides are outdated

I tried serval guides. Trying to do it on the project level

My DefaultEngine.ini

 [/Script/UnrealEd.UnrealEdEngine]
    +TemplateMapInfos=(ThumbnailTexture=Texture2D'/Game/Maps/Templates/Thumbnails/TemplateMap.TemplateMap',Map="/Game/Maps/Templates/TemplateMap")

In my content folder, I placed the template level in

Content/Maps/Templates

The thumbnail is in.

Content/Maps/Templates/Thumbnails

It turns out that you have to delete YourProject/Saved/Config/WindowsEditor/Engine.ini in order for your project-level TemplateMapInfos to be recognized.

Try that if your template map isn’t showing up in the “New Level” window.

In UE5, there’s a new way to do this now.
In Project Settings->Project->Maps & Modes, there’s a
‘Editor Template Map Overrides’ where you can edit an array of possible map templates.

Comment from the config field:
/** Map templates that should show up in the new level dialog. This will completely override the default maps chosen by the default editor */

Edit that array to point to your map templates, save, restart editor, and you’re good to go.