The original design of this product is made in a single phase 220V version with two terminals L & N, and also a 3 phase version with three L terminals and no Neutral connection.
The design you have appears to be a Chinese copy, with different components, with no legitimate safety approvals or authority to sell in countries requiring such.
The instructions with your product describe how to connect it to a 220V supply with a Line and Neutral connection (ie one wire at 220V and the other roughly at ground potential). You don't appear to have such a supply available.
The photo you provide of the connections throws serious doubt over the ability of the Neutral wiring to withstand the alleged 50A load current.
I don't think any responsible person on this forum will suggest you use it, or give you help remotely, given the risks it might pose.
Sorry to be so blunt, but just trying to explain why we are not leaping to help. I've spent the last couple of decades dealing with product standards and safety approvals of electrical and electronic products. You cannot just stare at product, or indeed just test it, and pronounce it safe for all users. It's a complicated business, and to be frank I don't have any reason to trust the safety of thing you have.
You are of course free to ignore the comments you receive here, but they are made with the best of intentions.
