This version fetches the correct boxart for TwilightMenu++ 9.5.0 and onwards. Make sure you have 'Adjust to correct aspect ratio' checked.
Windows Instructions
Download and run the EXE.
MacOS Instructions (untested)
Run TwilightBoxart.CLI using:
chmod +x TwilightBoxart.CLI
./TwilightBoxart.CLI
The MacOS version is huge because the .net framework is included.