Exporting for large LED screen

Hiya!

I need to export a portrait video for a large LED screen. The video I have right now is 1080x1920.

These are the technical requests that they provided

We would need a film on a 1920x1080 60 hz black canvas with the image in the top left corner. The resolution of the image/film in the video should be exactly 512 x 896 pixel. 

Does anyone possibly know what to do here?