UV-Paker for Unreal Engine
UV-Packer is avaliable for free on the Unreal Engine Marketplace and supports Unreal Engine 5.0 and up. You can find it here:
https://www.unrealengine.com/marketplace/en-US/product/uv-packer
Alternatively you can also search for UV-Packer directly in the Unreal Engine Marketplace section of your installed Epic Games Launcher.
UV-Packer for Unreal Engine is a free, fast and exact tool for automatic packing of UV maps. UV-Packer optimally packs even massive geometries with a single click without the need to leave Unreal Engine or reimport assets.
The main advantage of UV-Packer is the automatic workflow of rescaling UV clusters relative to the surface they cover on the mesh and arranges them to utilize as much space on the UV map as possible. This increases the texture quality for the mesh, fixes overlapping UV and results in optimized light maps.