I never tested on Unreal but it should work, maybe you didn't set the Blend Mode to Masked? You can try this post I did a while ago, it's the same workflow https://itch.io/post/4700055
Viewing post in Retro Modular Hedge Maze comments
Oh that makes sense it was basically turning a color into transparency then, no problem at all, I'm glad you managed to make it work, feel free to hit me up if you need any kind of assistance!
And I can't run Unreal Engine because I currently have no GPU on my desktop since mine broke down a cloupe of months ago, because of that my computer struggles to run Unity and Unreal doesn't even open anymore.