I think... but I'm not sure... that this is the same as the We R Memory Keepers Envelope Punchboard? I use it to make ALL of my envelopes (and I make a LOT). I love it! However, I don't use the instructions on the board itself.
For an A2 (5-1/2" x 4-1/4") card, I cut my paper to 8" square. I punch and score at 3-1/2". Then, rotate the paper 90 degrees and punch/score at 4-1/2". Rotate 90 degrees again, and punch/score at 3-1/2". Rotate once more 90 degrees, and punch/score at 4-1/2". Hopefully, that made sense.
For anything other than A2, I have an app on my phone, called Envelope Generator. I type in the size of my card, and it tells me what to cut my paper to, and where to score it.
I know I watched a YouTube video when I first got my punch board, and it helped to see someone actually use it. But if you can describe what's "not" working, maybe I can help more. Good luck! (I hate it when I can't get a tool to work. Anyone ever get a "straight" staple out of the old Fascinator?)