How do I connect 220V power switch?

Cameron

Hello, I need some help with my current project. I am converting a Chinese 3d printer to be controlled by a Duet 2 Wifi and trying to keep as many components original as possible. it originally came with this relay to control the 220V AC mains power.
Screen Shot 2020-05-09 at 1.03.21 PM.png

it looks like when you push the momentary switch the 220V turns on and allows power to flow to the boards and such. however if you let go of the momentary switch it stops. if i put 5V into the 5V IN on this board the 200V power is maintained. I am guessing the Signal In is to allow the Control Board to shut the machine down.
Screen Shot 2020-05-09 at 12.43.36 PM.png Screen Shot 2020-05-09 at 1.05.29 PM.png

Basically how can I supply 5V DC from the Duet 2 Wifi to this board to keep it on and can I use the Signal input to control this?