But I ran into an issue where I tried to use glue or weld surface in the windows of the door, but I make it unanchored so the door will work with hinges, but the windows from the door dropped and it was very unfortunate that I couldn’t find any help from Roblox Developer Wiki
I tried anchoring the window of the door but the door is stuck and not working and find any tools in the Roblox Studio and I got no luck finding it, I just needed help and I didn’t even get a response for days.
There’s an icon in the top toolbar (Model tab) in Studio for Constraints titled “Create”. There is a Weld tool there.
Click the “Show Welds” button next to it
First I’d make the glass all one single Part, just slightly smaller than the Union (about .02 studs smaller so it doesn’t appear in the sides of the door) and make it CanCollide True. Make your Union CanCollide False.
Select the Weld tool from the drop down list, then click on the Union, then click on the glass.
Done!