That ADT-link UT3G is the eGPU doc, you just need an ordinary PSU to power it and the GPU (I use an old one that I have). Though, to make everything work you might need time to fix quirks. E. g., I had to use "nvidia error 43 fixer" on Windows and to find a correct configuration on my Linux NixOS system (you need to load the Nvidia driver into the kernel in the boot process etc.). Here is how it looks https://imgur.com/a/qySDN4n