How do i output Fill and Key from a Blackmagic Decklink 8K Pro?

I am trying to output fill and key from a Declink 8k pro but i’m not getting any picture - not of fill and not of alpha. I saw a similar post that says to enable the 3d in the BM card but i can’t find any such option.

Has anyone managed to output fill and key through a BM card? If so can you please describe the process?


here is a quick guide to help you in setting up media profile for your Decklink in the engine:

and here is an important guide in helping you to setup Fill and Key output:

its important to understand how the composure works in unreal engine thats how you will accomplish your goal.